Implement Padding property in ImageButtonHandler

[jsuarezruiz]

Description of Change

Implement Padding property in ImageButton.

PR Checklist

• Targets the correct branch
• Tests are passing (or failures are unrelated)

Does this PR touch anything that might affect accessibility?

• No

[Redth]

@jsuarezruiz I don't see the padding value influencing MacCatalyst at all in the ImageButton gallery page.

[J-Swift]

@jsuarezruiz I happened to be looking into this because I noticed it wasn't implemented yet, and noticed that your Android implementation won't work as expected due to an Android Framework bug which pads the entire button rather than just the content area (material-components/material-components-android#2063).

This is what that looks like:

I propose the following for the Android implementation:

public static void UpdatePadding(this ShapeableImageView platformButton, IImageButton imageButton)
{
		var pad = imageButton.Padding;

		// NOTE(jpr): post on handler to get around an Android Framework bug.
		// see: https://github.com/material-components/material-components-android/issues/2063
		platformButton.Post(() =>
		{
				platformButton.SetContentPadding(
					(int)platformButton.Context.ToPixels(pad.Left),
					(int)platformButton.Context.ToPixels(pad.Top),
					(int)platformButton.Context.ToPixels(pad.Right),
					(int)platformButton.Context.ToPixels(pad.Bottom)
				);
		});
}

which results in this

[mattleibow]

The padding may be wrong and there might be an android bug that we need to work around.

[jsuarezruiz]

@jsuarezruiz I happened to be looking into this because I noticed it wasn't implemented yet, and noticed that your Android implementation won't work as expected due to an Android Framework bug which pads the entire button rather than just the content area (material-components/material-components-android#2063).

This is what that looks like:

I propose the following for the Android implementation:

public static void UpdatePadding(this ShapeableImageView platformButton, IImageButton imageButton)
{
		var pad = imageButton.Padding;

		// NOTE(jpr): post on handler to get around an Android Framework bug.
		// see: https://github.com/material-components/material-components-android/issues/2063
		platformButton.Post(() =>
		{
				platformButton.SetContentPadding(
					(int)platformButton.Context.ToPixels(pad.Left),
					(int)platformButton.Context.ToPixels(pad.Top),
					(int)platformButton.Context.ToPixels(pad.Right),
					(int)platformButton.Context.ToPixels(pad.Bottom)
				);
		});
}

which results in this

Used the Jimmy workaround. Thanks for include the issue.

[rmarinho]

Tests are failing on Android

https://dev.azure.com/xamarin/public/_build/results?buildId=58437&view=ms.vss-test-web.build-test-results-tab

[Redth]

/azp run

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