ESQueue:use 0x000001 instead of 0x00000001 as sync word in H264/MPEG_VIDEO

H264/MPEG_VIDEO sync words can be either 0x000001 (3 bytes) or
0x00000001 (4 bytes); simply searching for 0x000001 in appendData
suffices because:

1. 0x000001 is a suffix of 0x00000001, as such we would continue to
   identify all sync words that we used to identify originally.

2. the parsing logic downstream of appendData in
   dequeueAccessUnitMPEGVideo and dequeueAccessUnitH264
   can both handle 0x000001.

Bug: 19900317
Change-Id: Iac42aad74563d056a443b4396eacbae0f7a4738b