Bump to xamarin/Java.Interop/master@7228af0d

Changes: dotnet/java-interop@be58159...7228af0

Context: dotnet/java-interop#459

Updates `generator` so that all bound Java interfaces also implement
`IJavaPeerable` in addition to `IJavaObject`, for eventual future
C#8 Default Interface Member support.

[generator] Remove extraneous slash when creating .projitems.

[generator] Always use XAPeerMembers for XAJavaInterop1

Drop dependency on DylibMono when building for Xamarin.Android

[jnienv-gen] fix p/invoke usage for .NET framework

Add `jnimarshalmethod-gen.exe -r ASSEMBLY` option.

Improve support for binding package-private interfaces.

Parse EnclosingMethod, SourceFile annotation blobs.

Emit events for addListener(Listener,Handler) pattern

Fix `jnimarshalmethod-gen.exe`-related build error:

	Instance property 'PeerReference' is not defined for type 'Android.Widget.IListAdapter'
	Parameter name: propertyName
	System.ArgumentException: Instance property 'PeerReference' is not defined for type 'Android.Widget.IListAdapter'
	Parameter name: propertyName
	    at System.Linq.Expressions.Expression.Property (System.Linq.Expressions.Expression expression, System.String propertyName)
	    at Java.Interop.JavaPeerableValueMarshaler.CreateIntermediaryExpressionFromManagedExpression (Java.Interop.Expressions.JniValueMarshalerContext context, System.Linq.Expressions.ParameterExpression sourceValue)
	    at Java.Interop.JavaPeerableValueMarshaler.CreateReturnValueFromManagedExpression (Java.Interop.Expressions.JniValueMarshalerContext context, System.Linq.Expressions.ParameterExpression sourceValue)

Fix DylibMono build issues which prevented `src/monodroid` from
building.

build-tools/jnienv-gen/Generator.cs

@@ -390,7 +390,7 @@ static bool GenerateDefaultJavaInteropForwarder (TextWriter o, JniFunction entry
 				if (entry.Parameters [i].Type.ManagedType.StartsWith ("out "))
 					o.Write ("out ");
 				if (entry.Parameters [i].Type.ManagedType == "JValue*")
-					o.Write ("(JniArgumentValue*) " + Escape (entry.Parameters [i].Name));
+					o.Write ("(IntPtr) " + Escape (entry.Parameters [i].Name));
 				else if (IsObjectReferenceType (entry.Parameters [i].Type))
 					o.Write (string.Format ("new JniObjectReference ({0})", Escape (entry.Parameters [i].Name)));
 				else if (IsMemberID (entry.Parameters [i].Type)) {