Revert "audio: Add support for non-pcm VOIP vocoders"

This reverts commit 0a27eefad2e5289ab91c2d215a71d3b6a3802ea1.

Conflicts:

	media/libmedia/AudioTrack.cpp
	services/audioflinger/Threads.cpp
	services/audioflinger/Tracks.cpp

Change-Id: I35b431a79a5c54ed0b31086ff13ad8db9d82300c