Route UI thread lifecycle through platform services

src/app.cpp

@@ -20,8 +20,6 @@
 void android_async_lock();
 void android_async_swap();
 void android_async_unlock();
-void android_attach_jni();
-void android_detach_jni();
 #elif _WIN32
 bool async_lock_try();
 void async_lock();
@@ -1083,9 +1081,7 @@ void App::ui_thread_main()
     ui_thread_id = std::this_thread::get_id();
     ui_running = true;
 
-#if __ANDROID__
-    android_attach_jni();
-#endif
+    attach_ui_thread();
 
     LOG("ui thread init()");
     init();
@@ -1169,9 +1165,7 @@ void App::ui_thread_main()
             rendered_frames++;
         }
     }
-#if __ANDROID__
-    android_detach_jni();
-#endif
+    detach_ui_thread();
 }
 
 void App::render_thread_start()