Bump to xamarin/java.interop/main@320636d (#8512)

Changes: dotnet/java-interop@38c8a82...320636d

* [Java.Interop] Allow JniRuntime init from JavaVM* and JNIEnv*
* [Java.Interop.Tools.JavaCallableWrappers] [Export]+params
* [jcw-gen, jnimarshalmethod-gen] Native method consistency
* [generator] [JniConstructorSignature] on bound constructors
* Bump to dotnet/android-tools@8d38281