[Xamarin.Android.Build.Tasks] Feature for excluding Kotlin-related files from apps

[dellis1972]

Fixes #6920

Add a new ItemGroup AndroidPackagingOptionsExclude to the common targets. This ItemGroup will contain a set of RegEx compatible patterns which will be used to exclude certain files from the final apk/aab.

The patterns will need to be Url encoded so that MSBuild does not try to interpret them.

The main purpose of this is to allow us to exclude certain Kotlin meta-data files from the final package. These files seem to be excluded by gradle so we should do the same.

[dellis1972]

We will need this too https://github.com/xamarin/monodroid/pull/1265

[jonathanpeppers]

Otherwise, looks good if CI is green.

[jonpryor]

Fixes: https://github.com/xamarin/xamarin-android/issues/6920

Certainly NuGet packages pull in Kotlin-related artifacts which
aren't required at runtime.  These artifacts contribute to `.apk`
package size.

The [recommendation for native Android developers][0] is to
explicitly exclude these artifacts by using `packagingOptions`:

	packagingOptions {
	  exclude 'DebugProbesKt.bin'
	}

Xamarin.Android and .NET SDK for Android developers don't use Gradle,
so the above snippet is not useful.

Add support for a new `@(AndroidPackagingOptionsExclude)` item group.
This contains a "search pattern" a'la the `searchPattern` parameter
of [`Directory.EnumerateFiles(path, searchPattern)`][1], in which:

  * `*` matches 0 or more characters
  * `?` matches 1 character.

The default items within `@(AndroidPackagingOptionsExclude)` are:

  * `DebugProbesKt.bin`
  * `*.kotlin_*`

Files which match the search patterns within
`@(AndroidPackagingOptionsExclude)` are *excluded* from `.aab` and
`.apk` files, reducing app size.

[0]: https://github.com/Kotlin/kotlinx.coroutines/issues/2274
[1]: https://docs.microsoft.com/en-us/dotnet/api/system.io.directory.enumeratefiles?view=net-6.0#system-io-directory-enumeratefiles(system-string-system-string)