[build] ThirdPartyNotices.txt and $(CONFIGURATIONS) (dotnet#1367)

An unanticipated side-effect of commit 2bd13c4 was that
`make prepare` was downloading `bundle-v*.zip` for *both*
[Debug and Release][0] configurations, even on the PR builder (which
only builds Debug by default):

[0]: https://jenkins.mono-project.com/view/Xamarin.Android/job/xamarin-android-pr-builder/2610/console

	Downloading `https://xamjenkinsartifact.azureedge.net/xamarin-android/xamarin-android/bin/Debug/bundle-v21-h86de098f-Debug-Darwin-libzip=1d8b1ac,llvm=bdb3a11,mono=607cbde.zip` to `/Users/builder/android-archives/.bundle-v21-h86de098f-Debug-Darwin-libzip=1d8b1ac,llvm=bdb3a11,mono=607cbde.zip.download`
	...
	Downloading `https://xamjenkinsartifact.azureedge.net/xamarin-android/xamarin-android/bin/Release/bundle-v21-h86de098f-Release-Darwin-libzip=1d8b1ac,llvm=bdb3a11,mono=607cbde.zip` to `/Users/builder/android-archives/.bundle-v21-h86de098f-Release-Darwin-libzip=1d8b1ac,llvm=bdb3a11,mono=607cbde.zip.download`.

This is unneccessary, but was a result of:

	$(foreach c, $(CONFIGURATIONS), \
	  $(eval $(call CREATE_THIRD_PARTY_NOTICES ...)))

Since `ThirdPartyNotices.csproj` has a `@(ProjectReference)` to
`xa-prep-tasks.csproj`, the build of which attempts to download the
bundle, simply executing `ThirdPartyNotices.csproj` was triggering a
bundle download, which is not desired.

Rework the dependencies so that by default we only create
`bin/$(CONFIGURATION)/lib/xamarin.android/ThirdPartyNotices.txt`, not
one for all `$(CONFIGURATIONS)`, and move the `$(CONFIGURATIONS)`
logic into `make leeroy-all`.

Makefile

@@ -123,34 +123,39 @@ prepare-image-dependencies:
 include build-tools/scripts/BuildEverything.mk
 include tests/api-compatibility/api-compatibility.mk
 
-prepare:: prepare-tpn
-
 topdir  := $(shell pwd)
 
+# Usage: $(call CALL_CREATE_THIRD_PARTY_NOTICES,configuration,path,licenseType,includeExternalDeps,includeBuildDeps)
+define CREATE_THIRD_PARTY_NOTICES
+	$(MSBUILD) $(MSBUILD_FLAGS) $(_MSBUILD_ARGS) \
+		$(topdir)/build-tools/ThirdPartyNotices/ThirdPartyNotices.csproj \
+		/p:Configuration=$(1) \
+		/p:ThirdPartyNoticeFile=$(topdir)/$(2) \
+		/p:ThirdPartyNoticeLicenseType=$(3) \
+		/p:TpnIncludeExternalDependencies=$(4) \
+		/p:TpnIncludeBuildDependencies=$(5)
+endef # CREATE_THIRD_PARTY_NOTICES
+
+prepare:: prepare-tpn
+
 TPN_LICENSE_FILES = $(shell grep -h '<LicenseFile>' external/*.tpnitems src/*.tpnitems \
 	| sed -E 's,<LicenseFile>(.*)</LicenseFile>,\1,g;s,.\(MSBuildThisFileDirectory\),$(topdir)/external/,g' \
 	| tr \\ / )
 
 # Usage: $(call CREATE_THIRD_PARTY_NOTICES,configuration,path,licenseType,includeExternalDeps,includeBuildDeps)
-define CREATE_THIRD_PARTY_NOTICES
+define CREATE_THIRD_PARTY_NOTICES_RULE
 prepare-tpn:: $(2)
 
 $(2) $(topdir)/$(2): build-tools/ThirdPartyNotices/ThirdPartyNotices.csproj \
 		$(wildcard external/*.tpnitems src/*.tpnitems) \
 		$(TPN_LICENSE_FILES)
-	$(MSBUILD) $(MSBUILD_FLAGS) $(_MSBUILD_ARGS) $$< \
-		/p:Configuration=$(1) \
-		/p:ThirdPartyNoticeFile=$(topdir)/$(2) \
-		/p:ThirdPartyNoticeLicenseType=$(3) \
-		/p:TpnIncludeExternalDependencies=$(4) \
-		/p:TpnIncludeBuildDependencies=$(5)
-endef # CREATE_THIRD_PARTY_NOTICES
+	$(call CREATE_THIRD_PARTY_NOTICES,$(1),$(2),$(3),$(4),$(5))
+endef # CREATE_THIRD_PARTY_NOTICES_RULE
 
 THIRD_PARTY_NOTICE_LICENSE_TYPE = microsoft-oss
 
-$(eval $(call CREATE_THIRD_PARTY_NOTICES,$(CONFIGURATION),ThirdPartyNotices.txt,foundation,False,False))
-$(foreach c, $(CONFIGURATIONS), \
-	$(eval $(call CREATE_THIRD_PARTY_NOTICES,$(c),bin/$(c)/lib/xamarin.android/ThirdPartyNotices.txt,$(THIRD_PARTY_NOTICE_LICENSE_TYPE),True,False)))
+$(eval $(call CREATE_THIRD_PARTY_NOTICES_RULE,$(CONFIGURATION),ThirdPartyNotices.txt,foundation,False,False))
+$(eval $(call CREATE_THIRD_PARTY_NOTICES_RULE,$(CONFIGURATION),bin/$(CONFIGURATION)/lib/xamarin.android/ThirdPartyNotices.txt,$(THIRD_PARTY_NOTICE_LICENSE_TYPE),True,False))
 
 run-all-tests:
 	$(MSBUILD) $(MSBUILD_FLAGS) $(TEST_TARGETS) /t:RunAllTests

build-tools/scripts/BuildEverything.mk

@@ -101,7 +101,8 @@ leeroy: leeroy-all framework-assemblies opentk-jcw
 
 leeroy-all:
 	$(foreach conf, $(CONFIGURATIONS), \
-		$(_SLN_BUILD) $(MSBUILD_FLAGS) $(SOLUTION) /p:Configuration=$(conf) $(_MSBUILD_ARGS) && ) \
+		$(_SLN_BUILD) $(MSBUILD_FLAGS) $(SOLUTION) /p:Configuration=$(conf) $(_MSBUILD_ARGS) && \
+		$(call CREATE_THIRD_PARTY_NOTICES,$(conf),bin/$(conf)/lib/xamarin.android/ThirdPartyNotices.txt,$(THIRD_PARTY_NOTICE_LICENSE_TYPE),True,False) && ) \
 	true
 
 framework-assemblies: