- add zones to subscribe to allow selected subscription for
zoned properties
- extend config to uint32[4] to allow passing more informaiton
from configs
- change audio volume to be per context, not physical stream.
This maps better to android side's logical streams.
- renamed APP_CONTEXT to AUDIO_CONTEXT: It is useful only for
audio.
- add more audio contexts: safety alert, CD, aux audio
bug: 25183740, 26233321
Change-Id: I29de7b6c9d9a770cf87e7f50991c875d7ce9fdbe
bf877a7e66