libaudiohal: fix AIDL wrapper for offload playback

 - implement the setVolume function

 - fix drain command

 - return BAD_VALUE in getPlaybackRateParameters and
   setPlaybackRateParameters to avoid crashing

Bug: 270552159
Bug: 206737711
Test: mm libaudiohal@aidl
Test: play compressed offload streams
Change-Id: I49dc4c2432439f9473c89e9e908e69190e6b3676