MPEG2TSExtractor: support m2ts container

m2ts is based on the MPEG-2 transport stream container.
The standard MPEG2-2 TS 188-byte packet is prefixed with a
4-byte extra header to a total size of 192 bytes.

This patch makes MPEG2TSextractor support both
MPEG-2 transport stream and m2ts.

mts file use the same container as ts file

Bug: 123261411
Test: play m2ts file and check if it's normal
Change-Id: I7798a6bf3fcddf064d6bb6e39cd303bf83c3489e