In tizen_app_control's sendLaunchRequest(), user can specify a replyCallback.
When a replyCallback is specified, the embedder's app_control calls the reply callback and returns Success() (response).
If the application receiving app_control_send_launch_request() does not receive a reply response, _methodChannel.invokeMethod<dynamic>(‘sendLaunchRequest’,... ) will wating for response.

Therefore, we may need to change API from app_control_send_launch_request() to app_control_send_launch_request_async() to call the result callback event. or we can implement separate timeout logic.