Vorbis files may have more samples encoded that should be used, i.e. we have...

Vorbis files may have more samples encoded that should be used, i.e. we have to trim samples at the end of the stream. This is crucial for proper looping of some audio files.

related-to-bug: 3036592
Change-Id: Ib142b171c829ed74156c0281d9d4543fcc96c802