libstagefright: Polish MPEG4Writer for MediaMuxer.

     1. Fixed bug in Utils, which ignore 'ESDS' data for MPEG4 video.

    2. Add format limitation for MPEG4Writer.
       only support H.263/AVC/MPEG4 video and AAC/AMR-NB/AMR-WB audio.

Change-Id: I6daa9fa7c487d6cd95983d8b8da6f7fa53a2c44d
Signed-off-by: Anjun Wen <ajwen@marvell.com>