Allow multichannel FLAC files

FLACExtractor had artificial limits which did not allow multichannel
audio, 88.2 or 96 kHz samplerate, these were removed since it is up
to the audio subsystem to handle.

Change-Id: I700fab5509d3f15ec99e4acc194b061a88ae3257
Merge "Allow multichannel FLAC files" into jb4.2