Merge changes I22d9e018,Ib0701fcc,Ibc637918,I9eb7e002,I4adcec73

* changes:
  audioflinger: don't do work in constructor, instead do it in onFirstRef
  audioflinger: enumerate all the possible audio interfaces
  audio/media: convert to using the audio HAL and new audio defs
  libmedia: move AudioParameter out of AudioSystem
  audioflinger: move legacy audio hw/policy out to libhardware_legacy