NuPlayer: add support for proper stop

MediaPlayer.stop() should move to the Stopped state which is
semantically identical to the Initialized state.

Bug: 13138230
Change-Id: I5d7b4a22533f545c24a18e2cd9f7cb2685d42c84
Signed-off-by: Lajos Molnar <lajos@google.com>
2 files changed