Fixed a 'setVideoSurfaceTexture failed(-22)' after reset.

- The mPlayer is destructed if reference count becomes 0. But native object(MediaPlayerService::Client) is not destructed synchronously.
Native object is disconnected with nativewindow on destructor, But native object's destruction is sometimes deferred about 20ms even if mediaplayer::reset method is called.
If setVideoSurfaceTexture is called before native object's destructor, 'MediaPlayerService: setVideoSurfaceTexture failed: -22' error occured.
In order to prevent this error, native object should be disconnected with nativewindow before the reset method returns.

- Thread-Safe interface pattern(reset_l) does not seem to be usable in this case, so delete it.

- Use a local reference for reducing the range of mutex lock.

Change-Id: I2862e897003704393241d569b9398b23641ce8b9
Signed-off-by: sunjin.lee <sunjin.lee@lge.com>