omx: Add nBitsPerSample parameter for FLAC

 * Necessary to convey this information from the extractor.

Change-Id: Ic6f689df9d5f840280bf0410021f6d6ee04a48d5
Merge branch 'kk4.4-caf' of https://github.com/SlimRoms/frameworks_native into kk4.4-caf