Add support for using an Android Service to host the Godot engine

- Provide a `GodotService` Android service implementation which can be used to host an instance of the Godot engine
- Provide a `RemoteGodotFragment` Android fragment implementation which provides the view and logic to wrap connection to a `GodotService` instance

platform/android/java_godot_lib_jni.cpp

@@ -140,12 +140,12 @@ JNIEXPORT void JNICALL Java_org_godotengine_godot_GodotLib_setVirtualKeyboardHei
 	}
 }
 
-JNIEXPORT jboolean JNICALL Java_org_godotengine_godot_GodotLib_initialize(JNIEnv *env, jclass clazz, jobject p_activity, jobject p_godot_instance, jobject p_asset_manager, jobject p_godot_io, jobject p_net_utils, jobject p_directory_access_handler, jobject p_file_access_handler, jboolean p_use_apk_expansion) {
+JNIEXPORT jboolean JNICALL Java_org_godotengine_godot_GodotLib_initialize(JNIEnv *env, jclass clazz, jobject p_godot_instance, jobject p_asset_manager, jobject p_godot_io, jobject p_net_utils, jobject p_directory_access_handler, jobject p_file_access_handler, jboolean p_use_apk_expansion) {
 	JavaVM *jvm;
 	env->GetJavaVM(&jvm);
 
 	// create our wrapper classes
-	godot_java = new GodotJavaWrapper(env, p_activity, p_godot_instance);
+	godot_java = new GodotJavaWrapper(env, p_godot_instance);
 	godot_io_java = new GodotIOJavaWrapper(env, p_godot_io);
 
 	init_thread_jandroid(jvm, env);