libstagefright: Handle MPEG4 DP playback

Since the HW decoder doesn't support MPEG4 DP clips, detect DP
format clips in the parser and report a new MIME:
video/mpeg4-esdp. This MIME is only registered to the SW
decoder which supports DP clips.

Merges the following change from kitkat:
libstagefright: Fix DP Parsing issue with mpeg4 SP,ASP
(Change-Id: I69c719011e1a0d2a0b0ae5a9b504b7cce443866b)

CRs-Fixed: 722066
Change-Id: I7bc3a7a9f4a6d37e046ed9c8008cb27fb3bc665d