audio: new audio devices enums

Changes for new audio devices enums:
- legacy audio HAL wrapper provides conversion between new and
old device enums. It exposes a rev 2.0 audio device API to the
audio framework and allow legacy implementation to use old device enums.
- AudioPolicyManager: use standard enum value for no device (0).

Change-Id: I855d72291d672cdd8a6641bedb228634a54b7d9d
5 files changed