[Xamarin.Android.Build.Tasks] use mono.android.jar only for $(AndroidCodegenTarget)=XAJavaInterop1 (#9813)

`mono.android.jar` and `mono.android.dex` are compiled with
`$(AndroidCodegenTarget)=XAJavaInterop1`.  This causes problems if
you build a project with `$(AndroidCodegenTarget)=JavaInterop1`
as the wrong set of Java stubs will be used.

For example, `dotnet new maui` using NativAOT we can get a crash such as:

	E .hellonativeaot: No implementation found for void mono.android.Runtime.register(java.lang.String, java.lang.Class, java.lang.String) (tried Java_mono_android_Runtime_register and Java_mono_android_Runtime_register__Ljava_lang_String_2Ljava_lang_Class_2Ljava_lang_String_2) - is the library loaded, e.g. System.loadLibrary?

Which is caused by `mono.android.Runtime.register()` being called by
`mono/android/view/View_OnClickListenerImplementor.java` which is
compiled with `$(AndroidCodegenTarget)=XAJavaInterop1`.

To fix this:

  * Several places already check if `$(_AndroidUseMarshalMethods)=true`
    and skip usage of `mono.android.jar`.

  * Add an additional check to verify
    `$(AndroidCodegenTarget)=XAJavaInterop1`

Previously, `$(AndroidCodegenTarget)` was also allowed to be blank and
default to `XAJavaInterop1`, but it seems better to explicitly set it.

I also updated `BuildTest2.NativAOT()` to verify that
`mono/android/views/View_OnClickListenerImplementor.java` is
generated on disk.

Author: jonathanpeppers

src/Xamarin.Android.Build.Tasks/Tasks/GenerateJavaStubs.cs

@@ -440,11 +440,12 @@ IList<string> MergeManifest (NativeCodeGenState codeGenState, Dictionary<string,
 			List<TypeDefinition> allJavaTypes = scanner.GetJavaTypes (assemblies.Values, res);
 			var javaTypesForJCW = new List<TypeDefinition> ();
 
+			// When marshal methods or non-JavaPeerStyle.XAJavaInterop1 are in use we do not want to skip non-user assemblies (such as Mono.Android) - we need to generate JCWs for them during
+			// application build, unlike in Debug configuration or when marshal methods are disabled, in which case we use JCWs generated during Xamarin.Android
+			// build and stored in a jar file.
+			bool shouldSkipNonUserAssemblies = !useMarshalMethods && codeGenerationTarget == JavaPeerStyle.XAJavaInterop1;
 			foreach (TypeDefinition type in allJavaTypes) {
-				// When marshal methods are in use we do not want to skip non-user assemblies (such as Mono.Android) - we need to generate JCWs for them during
-				// application build, unlike in Debug configuration or when marshal methods are disabled, in which case we use JCWs generated during Xamarin.Android
-				// build and stored in a jar file.
-				if ((!useMarshalMethods && !userAssemblies.ContainsKey (type.Module.Assembly.Name.Name)) || JavaTypeScanner.ShouldSkipJavaCallableWrapperGeneration (type, cache)) {
+				if ((shouldSkipNonUserAssemblies && !userAssemblies.ContainsKey (type.Module.Assembly.Name.Name)) || JavaTypeScanner.ShouldSkipJavaCallableWrapperGeneration (type, cache)) {
 					continue;
 				}
 				javaTypesForJCW.Add (type);

src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/BuildTest2.cs

@@ -207,6 +207,10 @@ public void NativeAOT ()
 					"Should get log message about duplicate IOnClickListenerInvoker!");
 			}
 
+			// Verify that Java stubs for Mono.Android.dll were generated, instead of using mono.android.jar/dex
+			var onLayoutChangeListenerImplementor = Path.Combine (intermediate, "android", "src", "mono", "android", "view", "View_OnClickListenerImplementor.java");
+			FileAssert.Exists (onLayoutChangeListenerImplementor);
+
 			var dexFile = Path.Combine (intermediate, "android", "bin", "classes.dex");
 			FileAssert.Exists (dexFile);
 			foreach (var className in mono_classes) {

src/Xamarin.Android.Build.Tasks/Xamarin.Android.Common.targets

@@ -271,6 +271,7 @@ Copyright (C) 2011-2012 Xamarin. All rights reserved.
 	<AndroidApkSigningAlgorithm Condition=" '$(AndroidApkSigningAlgorithm)' == '' ">SHA256withRSA</AndroidApkSigningAlgorithm>
 	<AndroidApkDigestAlgorithm  Condition=" '$(AndroidApkDigestAlgorithm)' == '' ">SHA-256</AndroidApkDigestAlgorithm>
 	<AndroidManifestMerger      Condition=" '$(AndroidManifestMerger)' == '' ">manifestmerger.jar</AndroidManifestMerger>
+	<AndroidCodegenTarget       Condition=" '$(AndroidCodegenTarget)' == '' ">XAJavaInterop1</AndroidCodegenTarget>
 
 	<!-- Default Java heap size to 1GB (-Xmx1G) if not specified-->
 	<JavaMaximumHeapSize Condition=" '$(JavaMaximumHeapSize)' == '' ">1G</JavaMaximumHeapSize>
@@ -1382,7 +1383,9 @@ because xbuild doesn't support framework reference assemblies.
   <PropertyGroup>
     <_AndroidJarAndDexDirectory>$(_XATargetFrameworkDirectories)</_AndroidJarAndDexDirectory>
   </PropertyGroup>
-  <GetMonoPlatformJar Condition=" '$(_AndroidUseMarshalMethods)' != 'True' " TargetFrameworkDirectory="$(_AndroidJarAndDexDirectory)">
+  <GetMonoPlatformJar
+      Condition=" '$(_AndroidUseMarshalMethods)' != 'True' and '$(AndroidCodegenTarget)' == 'XAJavaInterop1' "
+      TargetFrameworkDirectory="$(_AndroidJarAndDexDirectory)">
     <Output TaskParameter="MonoPlatformJarPath" PropertyName="MonoPlatformJarPath" />
     <Output TaskParameter="MonoPlatformDexPath" PropertyName="MonoPlatformDexPath" />
   </GetMonoPlatformJar>
@@ -1410,12 +1413,12 @@ because xbuild doesn't support framework reference assemblies.
   />
 
   <Copy
-    Condition=" '$(_AndroidUseMarshalMethods)' != 'True' "
+    Condition=" '$(_AndroidUseMarshalMethods)' != 'True' and '$(AndroidCodegenTarget)' == 'XAJavaInterop1' "
     SourceFiles="$(MonoPlatformJarPath)"
     DestinationFiles="$(IntermediateOutputPath)android\bin\mono.android.jar"
     SkipUnchangedFiles="true" />
   <Touch
-    Condition=" '$(_AndroidUseMarshalMethods)' != 'True' "
+    Condition=" '$(_AndroidUseMarshalMethods)' != 'True' and '$(AndroidCodegenTarget)' == 'XAJavaInterop1' "
     Files="$(IntermediateOutputPath)android\bin\mono.android.jar" />
 
   <Touch Files="$(_AndroidStaticResourcesFlag)" AlwaysCreate="true" />
@@ -1424,7 +1427,10 @@ because xbuild doesn't support framework reference assemblies.
     <FileWrites Include="$(_AndroidIntermediateJavaSourceDirectory)mono\MonoRuntimeProvider.java" />
     <FileWrites Include="$(_AndroidIntermediateJavaSourceDirectory)mono\JavaInteropTypeManager.java" />
     <FileWrites Include="$(MonoAndroidIntermediateAssemblyDir)machine.config" />
-    <FileWrites Condition=" '$(_AndroidUseMarshalMethods)' != 'True' " Include="$(IntermediateOutputPath)android\bin\mono.android.jar" />
+    <FileWrites
+        Condition=" '$(_AndroidUseMarshalMethods)' != 'True' and '$(AndroidCodegenTarget)' == 'XAJavaInterop1' "
+        Include="$(IntermediateOutputPath)android\bin\mono.android.jar"
+    />
     <FileWrites Include="$(_AndroidStaticResourcesFlag)" />
   </ItemGroup>
 </Target>