media.MediaMuxer: remove unused SAMPLE_FLAG_SYNC flag.

This is not actually used, and introduces flag translation
code for all users of this new MediaMuxer API.

Change-Id: I8baa2b13d7e637142f6e3b18a170e6329b90bd5e
Signed-off-by: Lajos Molnar <lajos@google.com>
Bug: 9169479
1 file changed