Gallery2: fix video playback after system language change

- when system language changed, the activity would be destroyed
  and recreated. The subobject MoviePlayer would be also recreated.
  But in this case, MoviePlayer doesn't set some parameters like
  the URI, duration and etc. It cause the video playback failed.
- add the related function calls to restart the video playback.

(cherry picked from commit 59890ad484be36860f9ad326cdcda292111e3513)

Change-Id: Ie9c46ddbea2b9826988c1fa7e8e7c1c99e2606f7