[linker] preserve interfaces on Java types

Fixes: #7097
Context: xamarin/monodroid@a619cbe

Usage of a `Google.Android.Material.TextField.TextInputEditText`:

    var filterBox = FindViewById<TextInputEditText>(Resource.Id.filterBox);
    filterBox.TextChanged += (s, e) => { };

Crashes at runtime with:

    android.runtime.JavaProxyThrowable: System.TypeLoadException: Could not load type '{0}' from assembly '{1}'., Android.Text.ITextWatcherInvoker, Mono.Android, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null
        at System.RuntimeTypeHandle.GetTypeByName(String , Boolean , Boolean , StackCrawlMark& , Boolean )
        at System.RuntimeType.GetType(String , Boolean , Boolean , StackCrawlMark& )
        at System.Type.GetType(String , Boolean )
        at Android.Runtime.AndroidTypeManager.RegisterNativeMembers(JniType , Type , ReadOnlySpan`1 )
    --- End of stack trace from previous location ---
        at Java.Interop.JniEnvironment.StaticMethods.CallStaticObjectMethod(JniObjectReference , JniMethodInfo , JniArgumentValue* )
        at Android.Runtime.JNIEnv.FindClass(String )
        at Android.Runtime.JNIEnv.AllocObject(String )
        at Android.Runtime.JNIEnv.StartCreateInstance(String , String , JValue* )
        at Android.Runtime.JNIEnv.StartCreateInstance(String , String , JValue[] )
        at Android.Text.TextWatcherImplementor..ctor(Object , EventHandler`1 , EventHandler`1 , EventHandler`1 )
        at Android.Widget.TextView.add_TextChanged(EventHandler`1 )
        at AndroidApp1.MainActivity.OnCreate(Bundle savedInstanceState)
        at Android.App.Activity.n_OnCreate_Landroid_os_Bundle_(IntPtr , IntPtr , IntPtr )
        at Android.Runtime.JNINativeWrapper.Wrap_JniMarshal_PPL_V(_JniMarshal_PPL_V , IntPtr , IntPtr , IntPtr )
        at crc64a6e0c00971f6cd91.MainActivity.n_onCreate(Native Method)
        at crc64a6e0c00971f6cd91.MainActivity.onCreate(MainActivity.java:29)

The problem being that the linker completely removed the
`ITextWatcher` interface, and the
`Android.Text.TextWatcherImplementor` type no longer implemented that
interface.

It appears we should preserve interfaces in .NET 6 for Java types
*except* if the type defines:

    [Android.Runtime.Register (DoNotGenerateAcw = true)]

This is on types like `Android.App.Activity` where we would *not* need
to preserve all the interfaces.

However, types like `TextWatcherImplementor` would get their
interfaces preserved appropriately.

src/Xamarin.Android.Build.Tasks/Linker/MonoDroid.Tuner/MarkJavaObjects.cs

@@ -60,6 +60,9 @@ void PreserveJavaObjectImplementation (TypeDefinition type)
 			PreserveIntPtrConstructor (type);
 			PreserveAttributeSetConstructor (type);
 			PreserveInvoker (type);
+#if ILLINK
+			PreserveInterfaces (type);
+#endif // ILLINK
 		}
 
 		void PreserveAttributeSetConstructor (TypeDefinition type)
@@ -196,7 +199,38 @@ void PreserveInvoker (TypeDefinition type)
 			PreserveConstructors (type, invoker);
 			PreserveIntPtrConstructor (invoker);
 			PreserveInterfaceMethods (type, invoker);
+#if ILLINK
+			PreserveInterfaces (invoker);
+#endif // ILLINK
+		}
+
+#if ILLINK
+		void PreserveInterfaces (TypeDefinition type)
+		{
+			if (!type.HasInterfaces)
+				return;
+
+			// Return if [Register(DoNotGenerateAcw=true)] is on the type
+			if (type.HasCustomAttributes) {
+				foreach (var attr in type.CustomAttributes) {
+					if (attr.AttributeType.FullName == "Android.Runtime.RegisterAttribute") {
+						foreach (var property in attr.Properties) {
+							if (property.Name == "DoNotGenerateAcw") {
+								if (property.Argument.Value is bool value && value)
+									return;
+								break;
+							}
+						}
+						break;
+					}
+				}
+			}
+
+			foreach (var iface in type.Interfaces) {
+				Annotations.Mark (iface.InterfaceType.Resolve ());
+			}
 		}
+#endif // ILLINK
 
 		TypeDefinition GetInvokerType (TypeDefinition type)
 		{

tests/MSBuildDeviceIntegration/Resources/LinkDescTest/MainActivityReplacement.cs

@@ -115,6 +115,9 @@ protected override void OnCreate(Bundle bundle)
 			// [Test] Post
 			Android.Util.Log.Info(TAG, HttpClientTest.Post ());
 
+			// [Test] TextChanged
+			Android.Util.Log.Info (TAG, MaterialTextChanged.TextChanged (this));
+
 			var cldt = new CustomLinkerDescriptionTests();
 			Android.Util.Log.Info(TAG, cldt.TryAccessNonXmlPreservedMethodOfLinkerModeFullClass());
 			Android.Util.Log.Info(TAG, LinkTestLib.Bug21578.MulticastOption_ShouldNotBeStripped());

tests/MSBuildDeviceIntegration/Resources/LinkDescTest/MaterialTextChanged.cs

@@ -0,0 +1,18 @@
+using System;
+using Android.Content;
+using Google.Android.Material.TextField;
+
+public class MaterialTextChanged
+{
+	// [Test]
+	public static string TextChanged (Context context)
+	{
+		try {
+			var view = new TextInputEditText (context);
+			view.TextChanged += (s, e) => { };
+			return $"[PASS] {nameof (MaterialTextChanged)}.{nameof (TextChanged)}";
+		} catch (Exception ex) {
+			return $"[FAIL] {nameof (MaterialTextChanged)}.{nameof (TextChanged)} FAILED: {ex}";
+		}
+	}
+}

tests/MSBuildDeviceIntegration/Tests/InstallAndRunTests.cs

@@ -421,6 +421,24 @@ public class LinkModeFullClass {
 					new BuildItem ("ProjectReference", "..\\Library1\\Library1.csproj"),
 					new BuildItem ("ProjectReference", "..\\LinkTestLib\\LinkTestLib.csproj"),
 				},
+				PackageReferences = {
+					KnownPackages.AndroidXMigration,
+					KnownPackages.AndroidXAppCompat,
+					KnownPackages.AndroidXAppCompatResources,
+					KnownPackages.AndroidXBrowser,
+					KnownPackages.AndroidXMediaRouter,
+					KnownPackages.AndroidXLegacySupportV4,
+					KnownPackages.AndroidXLifecycleLiveData,
+					KnownPackages.XamarinGoogleAndroidMaterial,
+				},
+				Sources = {
+					new BuildItem.Source ("MaterialTextChanged.cs") {
+						TextContent = () => {
+							using (var sr = new StreamReader (typeof (InstallAndRunTests).Assembly.GetManifestResourceStream ("Xamarin.Android.Build.Tests.Resources.LinkDescTest.MaterialTextChanged.cs")))
+								return sr.ReadToEnd ();
+						},
+					},
+				},
 				OtherBuildItems = {
 					new BuildItem ("LinkDescription", "linker.xml") {
 						TextContent = () => linkMode == AndroidLinkMode.SdkOnly ? "<linker/>" : @"