Libstagefright: Fix crash while setting buffer size

The format returned from MakeAVCCodecSpecificData may be
NULL and will crash on trying to set buffer size.

Added NULL check to avoid crash

Conflicts:
	media/libstagefright/mpeg2ts/ESQueue.cpp

Change-Id: I45485f820a6aa657e63aeeb6dd43061a2e3575e3
Merge "Libstagefright: Fix crash while setting buffer size" into du44