OpenSL ES audio players are accounted for in AudioService

Track activity of AudioPlayer instances that play audio,
  i.e. those with an AudioTrack. Assign them a player
  interface ID, and report their state through
  the native interface for AudioService.

Test: launch app using SL ES and dump AudioService
Bug: 30955183

Change-Id: I02dc0a34779b08f44d7c58b010932e1c6335b415