Revert "[Mono.Android] Add [Category] for IDE completion of string pr…

…ops (dotnet#2866)" (dotnet#5375)

Fixes: dotnet#5373

Reverts: d548ec9
Reverts: dotnet#2862

The idea in Issue dotnet#2862 and commit d548ec9 was to to improve code
completion for Android Resources within Visual Studio:

![Android Resource completion in Visual Studio][0]

This was achieved by adding [`CategoryAttribute`][1] to various
properties so that Visual Studio could know what completions to show:

	partial class ActivityAttribute {
	    [System.ComponentModel.Category ("@string")]
	    public string?                Label                   {get; set;}
	}

Unfortunately, the presence of `CategoryAttribute` causes the .NET 6
linker to preserve various dependencies of `System.ComponentModel`,
causing `.apk` files to be larger than desired.

Furthermore, the feature was *experimental*, and never shipped in a
stable Visual Studio release.

For now, revert commit d548ec9, removing the `[Category]` custom
attributes.  This will allow `.apk` files to be smaller for .NET 6.

Should we want to bring this feature back, we'll either need to see
if the linker can be improved to remove `CategoryAttribute`, or
instead introduce a set of `internal` attributes for this purpose.

Results of this change in a .NET 6 `.apk`:

	> apkdiff before.apk after.apk
	Size difference in bytes ([*1] apk1 only, [*2] apk2 only):
	-          56 lib/armeabi-v7a/libxamarin-app.so
	Section size difference
	-           8 .rel.dyn
	-          12 .data
	-       6,144 .bss
	-          77 assemblies/Mono.Android.dll
	-       3,194 assemblies/System.ComponentModel.Primitives.dll *1
	Summary:
	+           0 Other entries 0.00% (of 6,484)
	+           0 Dalvik executables 0.00% (of 317,508)
	-       3,271 Assemblies -0.15% (of 2,139,234)
	-          56 Shared libraries -0.00% (of 20,674,428)
	-       3,468 Package size difference -0.04% (of 9,485,287)

[0]: https://user-images.githubusercontent.com/169707/54777844-f9b37500-4bf1-11e9-8e52-63982b8b362f.gif
[1]: https://docs.microsoft.com/dotnet/api/system.componentmodel.categoryattribute?view=netframework-4.7.2

Documentation/release-notes/5375.md

@@ -0,0 +1,25 @@
+### Application size improvements
+
+  * [GitHub PR 5375](https://github.com/xamarin/xamarin-android/pull/5375):
+    Removed decoration of `System.ComponentModel.CategoryAttribute` to
+    improve linker behavior. This reduced the .NET assembly size of a
+    .NET 6 application by 3,271 bytes.
+
+`CategoryAttribute` was removed from properties on types such as
+`Android.App.ActivityAttribute`:
+
+```diff
+-[Category ("@drawable;@mipmap")]
+public string? Icon { get; set; }
+-[Category ("@string")]
+public string? Label { get; set; }
+```
+
+A full list of types changed:
+
+* `Android.App.ActivityAttribute`
+* `Android.App.ApplicationAttribute`
+* `Android.App.InstrumentationAttribute`
+* `Android.App.ServiceAttribute`
+* `Android.Content.BroadcastReceiverAttribute`
+* `Android.Content.ContentProviderAttribute`

src/Xamarin.Android.NamingCustomAttributes/Android.App/ActivityAttribute.cs

@@ -1,5 +1,4 @@
 using System;
-using System.ComponentModel;
 
 using Android.Content.PM;
 using Android.Views;
@@ -53,9 +52,7 @@ public ActivityAttribute ()
 #if ANDROID_11
 		public bool                   HardwareAccelerated     {get; set;}
 #endif
-		[Category ("@drawable;@mipmap")]
 		public string?                Icon                    {get; set;}
-		[Category ("@string")]
 		public string?                Label                   {get; set;}
 		public LaunchMode             LaunchMode              {get; set;}
 #if ANDROID_23
@@ -102,7 +99,6 @@ public ActivityAttribute ()
 		public WindowRotationAnimation      RotationAnimation    {get; set;}
 #endif
 #if ANDROID_25
-		[Category ("@drawable;@mipmap")]
 		public string?                RoundIcon               {get; set;}
 #endif
 #if ANDROID_23
@@ -124,7 +120,6 @@ public ActivityAttribute ()
 #endif
 		public bool                   StateNotNeeded          {get; set;}
 		public string?                TaskAffinity            {get; set;}
-		[Category ("@style")]
 		public string?                Theme                   {get; set;}
 #if ANDROID_27
 		public bool                   TurnScreenOn            {get; set;}

src/Xamarin.Android.NamingCustomAttributes/Android.App/ApplicationAttribute.cs

@@ -1,5 +1,4 @@
 using System;
-using System.ComponentModel;
 
 using Android.Content.PM;
 using Android.Views;
@@ -31,7 +30,6 @@ public ApplicationAttribute ()
 		public string?                Banner                  {get; set;}
 #endif
 		public bool                   Debuggable              {get; set;}
-		[Category ("@string")]
 		public string?                Description             {get; set;}
 #if ANDROID_24
 		public bool                   DirectBootAware         {get; set;}
@@ -48,16 +46,13 @@ public ApplicationAttribute ()
 		public bool                   HardwareAccelerated     {get; set;}
 #endif
 		public bool                   HasCode                 {get; set;}
-		[Category ("@drawable;@mipmap")]
 		public string?                Icon                    {get; set;}
 		public bool                   KillAfterRestore        {get; set;}
 #if ANDROID_11
 		public bool                   LargeHeap               {get; set;}
 #endif
-		[Category ("@string")]
 		public string?                Label                   {get; set;}
 #if ANDROID_11
-		[Category ("@drawable;@mipmap")]
 		public string?                Logo                    {get; set;}
 #endif
 		public Type?                  ManageSpaceActivity     {get; set;}
@@ -75,14 +70,12 @@ public ApplicationAttribute ()
 		public string?                RestrictedAccountType   {get; set;}
 #endif
 #if ANDROID_25
-		[Category ("@drawable;@mipmap")]
 		public string?                RoundIcon               {get; set;}
 #endif
 #if ANDROID_17
 		public bool                   SupportsRtl             {get; set;}
 #endif
 		public string?                TaskAffinity            {get; set;}
-		[Category ("@style")]
 		public string?                Theme                   {get; set;}
 #if ANDROID_14
 		public UiOptions              UiOptions               {get; set;}

src/Xamarin.Android.NamingCustomAttributes/Android.App/InstrumentationAttribute.cs

@@ -1,5 +1,4 @@
 using System;
-using System.ComponentModel;
 
 namespace Android.App {
 
@@ -15,13 +14,10 @@ public InstrumentationAttribute ()
 
 		public bool                   FunctionalTest  {get; set;}
 		public bool                   HandleProfiling {get; set;}
-		[Category ("@drawable;@mipmap")]
 		public string?                Icon            {get; set;}
-		[Category ("@string")]
 		public string?                Label           {get; set;}
 		public string?                Name            {get; set;}
 #if ANDROID_25
-		[Category ("@drawable;@mipmap")]
 		public string?                RoundIcon               {get; set;}
 #endif
 		public string?                TargetPackage   {get; set;}

src/Xamarin.Android.NamingCustomAttributes/Android.App/ServiceAttribute.cs

@@ -1,5 +1,4 @@
 using System;
-using System.ComponentModel;
 
 using Android.Content.PM;
 using Android.Views;
@@ -26,17 +25,14 @@ public ServiceAttribute ()
 #if ANDROID_29
 		public ForegroundService      ForegroundServiceType   {get; set;}
 #endif
-		[Category ("@drawable;@mipmap")]
 		public string?                Icon                    {get; set;}
 #if ANDROID_16
 		public bool                   IsolatedProcess         {get; set;}
 #endif
-		[Category ("@string")]
 		public string?                Label                   {get; set;}
 		public string?                Permission              {get; set;}
 		public string?                Process                 {get; set;}
 #if ANDROID_25
-		[Category ("@drawable;@mipmap")]
 		public string?                RoundIcon               {get; set;}
 #endif
 	}

src/Xamarin.Android.NamingCustomAttributes/Android.Content/BroadcastReceiverAttribute.cs

@@ -1,5 +1,4 @@
 using System;
-using System.ComponentModel;
 
 namespace Android.Content {
 
@@ -16,17 +15,13 @@ public BroadcastReceiverAttribute ()
 		public bool                   DirectBootAware         {get; set;}
 		public bool                   Enabled                 {get; set;}
 		public bool                   Exported                {get; set;}
-		[Category ("@string")]
 		public string?                Description             {get; set;}
-		[Category ("@drawable;@mipmap")]
 		public string?                Icon                    {get; set;}
-		[Category ("@string")]
 		public string?                Label                   {get; set;}
 		public string?                Name                    {get; set;}
 		public string?                Permission              {get; set;}
 		public string?                Process                 {get; set;}
 #if ANDROID_25
-		[Category ("@drawable;@mipmap")]
 		public string?                RoundIcon               {get; set;}
 #endif
 	}

src/Xamarin.Android.NamingCustomAttributes/Android.Content/ContentProviderAttribute.cs

@@ -1,5 +1,4 @@
 using System;
-using System.ComponentModel;
 
 namespace Android.Content {
 
@@ -25,18 +24,15 @@ public ContentProviderAttribute (string[] authorities)
 		public bool                   Enabled                 {get; set;}
 		public bool                   Exported                {get; set;}
 		public bool                   GrantUriPermissions     {get; set;}
-		[Category ("@drawable;@mipmap")]
 		public string?                Icon                    {get; set;}
 		public int                    InitOrder               {get; set;}
-		[Category ("@string")]
 		public string?                Label                   {get; set;}
 		public bool                   MultiProcess            {get; set;}
 		public string?                Name                    {get; set;}
 		public string?                Permission              {get; set;}
 		public string?                Process                 {get; set;}
 		public string?                ReadPermission          {get; set;}
 #if ANDROID_25
-		[Category ("@drawable;@mipmap")]
 		public string?                RoundIcon               {get; set;}
 #endif
 		public bool                   Syncable                {get; set;}

tests/api-compatibility/acceptable-breakages-vReference.txt

@@ -0,0 +1,24 @@
+Compat issues with assembly Mono.Android:
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.App.ActivityAttribute.Icon' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.App.ActivityAttribute.Label' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.App.ActivityAttribute.RoundIcon' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.App.ActivityAttribute.Theme' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.App.ApplicationAttribute.Description' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.App.ApplicationAttribute.Icon' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.App.ApplicationAttribute.Label' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.App.ApplicationAttribute.Logo' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.App.ApplicationAttribute.RoundIcon' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.App.ApplicationAttribute.Theme' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.App.InstrumentationAttribute.Icon' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.App.InstrumentationAttribute.Label' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.App.InstrumentationAttribute.RoundIcon' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.App.ServiceAttribute.Icon' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.App.ServiceAttribute.Label' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.App.ServiceAttribute.RoundIcon' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.Content.BroadcastReceiverAttribute.Description' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.Content.BroadcastReceiverAttribute.Icon' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.Content.BroadcastReceiverAttribute.Label' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.Content.BroadcastReceiverAttribute.RoundIcon' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.Content.ContentProviderAttribute.Icon' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.Content.ContentProviderAttribute.Label' in the contract but not the implementation.
+CannotRemoveAttribute : Attribute 'System.ComponentModel.CategoryAttribute' exists on 'Android.Content.ContentProviderAttribute.RoundIcon' in the contract but not the implementation.