[xabt] remove $(_AndroidAllowDeltaInstall) (#10237)

Context: https://github.com/MicrosoftDocs/xamarin-docs/blob/0506e3bf14b520776fc7d33781f89069bbc57138/docs/android/deploy-test/apply-changes.md 
Fixes: #10188

This PR removes the `$(_AndroidAllowDeltaInstall)` MSBuild property
and related infrastructure as this feature has been removed from IDEs.

## Changes Made

- **Removed property constant**: Eliminated
  `_AndroidAllowDeltaInstall` from `KnownProperties.cs`
- **Updated test cases**: Modified `DebuggingTest.cs` to remove the
  `allowDeltaInstall` parameter from all test cases and removed one
  test case that specifically tested the delta install functionality
- **Removed NuGet feed**: Eliminated the "xamarin.android util" feed
  from `NuGet.config` that was used for the
  `Xamarin.Android.Deploy.Installer` package

## Bump android-platform-support

Bump to DevDiv/android-platform-support/main@a8c83d7e

Changes: https://devdiv.visualstudio.com/DevDiv/_git/android-platform-support/branchCompare?baseVersion=GCba980b15c8d61f10d902602ad4e614423f39b43a&targetVersion=GCa8c83d7e7f77634433086d79fa3674f63cef3098

* [xabdt] Remove `$(_AndroidAllowDeltaInstall)` support

* Bump to dotnet/android-tools@d4b55297

* Update `Feeds\README.md` for `$XAMARIN_ANDROID_MANIFEST_URL`

## Files Modified

- `src/Xamarin.Android.Build.Tasks/Tests/Xamarin.ProjectTools/Android/KnownProperties.cs`
  - Removed property constant
- `tests/MSBuildDeviceIntegration/Tests/DebuggingTest.cs` - Updated
  test method signature and test cases
- `NuGet.config` - Removed deprecated NuGet feed and related comments

The changes are minimal and surgical, removing only the specific delta
install functionality without affecting other features. No
`PackageReference` to `Xamarin.Android.Deploy.Installer` was found in
the codebase, and no related .dll files exist in the repository.

Co-authored-by: Jonathan Peppers <[email protected]>

Author: Copilot

.external

@@ -1 +1 @@
-DevDiv/android-platform-support:main@ba980b15c8d61f10d902602ad4e614423f39b43a
+DevDiv/android-platform-support:main@a8c83d7e7f77634433086d79fa3674f63cef3098

NuGet.config

@@ -16,9 +16,6 @@
     <add key="dotnet9-transport" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet9-transport/nuget/v3/index.json" />
     <add key="dotnet10" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet10/nuget/v3/index.json" />
     <add key="dotnet10-transport" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet10-transport/nuget/v3/index.json" />
-    <!-- This is needed (currently) for the Xamarin.Android.Deploy.Installer dependency, getting the installer -->
-    <!-- Android binary, to support delta APK install -->
-    <add key="xamarin.android util" value="https://pkgs.dev.azure.com/xamarin/public/_packaging/Xamarin.Android/nuget/v3/index.json" />
     <!-- Added manually for dotnet/runtime 9.0.5 -->
     <add key="darc-pub-dotnet-emsdk-3cddc1f" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/darc-pub-dotnet-emsdk-3cddc1fe/nuget/v3/index.json" />
     <add key="darc-pub-dotnet-runtime-207cda3" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/darc-pub-dotnet-runtime-207cda34/nuget/v3/index.json" />

src/Xamarin.Android.Build.Tasks/Tests/Xamarin.ProjectTools/Android/KnownProperties.cs

@@ -33,7 +33,6 @@ public static class KnownProperties
 		public const string IntermediateOutputPath = "IntermediateOutputPath";
 		public const string OutputType = "OutputType";
 		public const string AndroidClassParser = "AndroidClassParser";
-		public const string _AndroidAllowDeltaInstall = "_AndroidAllowDeltaInstall";
 		public const string Nullable = "Nullable";
 		public const string ImplicitUsings = "ImplicitUsings";
 		public const string PublishAot = "PublishAot";

tests/MSBuildDeviceIntegration/Tests/DebuggingTest.cs

@@ -283,70 +283,54 @@ public override void OnCreate ()
 		static object [] DebuggerTestCases = new object [] {
 			new object[] {
 				/* embedAssemblies */    true,
-				/* allowDeltaInstall */  false,
 				/* user */		 null,
 				/* packageFormat */      "apk",
 				/* useLatestSdk */       true,
 			},
 			new object[] {
 				/* embedAssemblies */    true,
-				/* allowDeltaInstall */  false,
 				/* user */		 null,
 				/* packageFormat */      "apk",
 				/* useLatestSdk */       false,
 			},
 			new object[] {
 				/* embedAssemblies */    false,
-				/* allowDeltaInstall */  false,
-				/* user */		 null,
-				/* packageFormat */      "apk",
-				/* useLatestSdk */       true,
-			},
-			new object[] {
-				/* embedAssemblies */    false,
-				/* allowDeltaInstall */  true,
 				/* user */		 null,
 				/* packageFormat */      "apk",
 				/* useLatestSdk */       true,
 			},
 			new object[] {
 				/* embedAssemblies */    true,
-				/* allowDeltaInstall */  false,
 				/* user */		 DeviceTest.GuestUserName,
 				/* packageFormat */      "apk",
 				/* useLatestSdk */       true,
 			},
 			new object[] {
 				/* embedAssemblies */    false,
-				/* allowDeltaInstall */  false,
 				/* user */		 DeviceTest.GuestUserName,
 				/* packageFormat */      "apk",
 				/* useLatestSdk */       true,
 			},
 			new object[] {
 				/* embedAssemblies */    true,
-				/* allowDeltaInstall */  false,
 				/* user */		 null,
 				/* packageFormat */      "aab",
 				/* useLatestSdk */       true,
 			},
 			new object[] {
 				/* embedAssemblies */    false,
-				/* allowDeltaInstall */  false,
 				/* user */		 null,
 				/* packageFormat */      "aab",
 				/* useLatestSdk */       true,
 			},
 			new object[] {
 				/* embedAssemblies */    true,
-				/* allowDeltaInstall */  false,
 				/* user */		 DeviceTest.GuestUserName,
 				/* packageFormat */      "aab",
 				/* useLatestSdk */       true,
 			},
 			new object[] {
 				/* embedAssemblies */    false,
-				/* allowDeltaInstall */  false,
 				/* user */		 DeviceTest.GuestUserName,
 				/* packageFormat */      "aab",
 				/* useLatestSdk */       true,
@@ -357,7 +341,7 @@ public override void OnCreate ()
 		[Test, Category ("Debugger"), Category ("WearOS")]
 		[TestCaseSource (nameof(DebuggerTestCases))]
 		[Retry (5)]
-		public void ApplicationRunsWithDebuggerAndBreaks (bool embedAssemblies, bool allowDeltaInstall, string username, string packageFormat, bool useLatestSdk)
+		public void ApplicationRunsWithDebuggerAndBreaks (bool embedAssemblies, string username, string packageFormat, bool useLatestSdk)
 		{
 			AssertCommercialBuild ();
 			SwitchUser ();
@@ -409,7 +393,6 @@ public Foo ()
 			app.AddReference (lib);
 			var abis = new [] { DeviceAbi };
 			app.SetRuntimeIdentifiers (abis);
-			app.SetProperty (KnownProperties._AndroidAllowDeltaInstall, allowDeltaInstall.ToString ());
 			app.SetDefaultTargetDevice ();
 			using (var libBuilder = CreateDllBuilder (Path.Combine (path, lib.ProjectName)))
 			using (var appBuilder = CreateApkBuilder (Path.Combine (path, app.ProjectName))) {