Merge "stagefright: MPEG4Extractor: allow \'hdlr\' box before first track" into klp-dev am: b1a13d01dc am: 781cd4f37d am: 8565726f57 am: b44e95da77 am: 699e9b0749
am: 8e4f53159c

* commit '8e4f53159c64996e1617ec589977c290fa233010':
  stagefright: MPEG4Extractor: allow 'hdlr' box before first track