Revert "[rbp/omxplayer] Move buffering decision out of OMXPlayerAudio"

This reverts commit 8312a6d3647da686d4350baaa3c6ee87eaa29d60.
Revert "[rbp/omxplayer] Move buffering to omxplayer level"

This reverts commit 19e7b4e17d3c2c2f3c3046447a59f34cef4f920e.