[ARDrone][Video] Refactor code to allow use android.media.MediaMuxer

A new abstract class Mp4Muxer is generated. This class allow to switch
different mp4muxer backed on the fly. Use android.media.MediaMuxer when
API level >= 18(JELLY_BEAN_MR2), otherwise fall back to use the
mp4parser one.

Because of crash on muxer.stop(), the current code does not do invoke
the MediaMuxer code at all and leave a TODO.