AudioTrack: Reject offloading for non-music streams

Reject AudioTrack initialization if called with non-music
stream type (or attribute) but with AUDIO_OUTPUT_FLAG_COMPRESS_OFFLOAD.

This will allow the client to fall back to SW decode or
deal with the error appropriately.

CRs-Fixed: 740607
Change-Id: I4d1dda6523bd792ab26b0363e16febcd14b1ad98