Set audio mode after accepting the call

Set the audio mode to incall immediately after accepting the call and not wait
till call is reported as ACTIVE by RIL. This is done to speed up time taken for audio
to set up the voice path

(CM change: Remove calls to Rlog, since we haven't imported that yet)

Bug: 7612431
Change-Id: I8008edc64928016ab94aa6d770de248b5d85dc93
Fix ringing audio focus handling.

Test case:
- enable increasing ringtone starting at volume 0
- start any music player
- get an incoming call

Previous behaviour:
When ringtone volume is increased from 0 to 1, music continues playing
even
though ring tone is playing as well.

New behaviour:
When ringtone starts, music is attenuated to make user aware of incoming
call. When ringtone volume is increased to 1, music stops playing.

Change-Id: Ifc32ea162d4527572be0574024116d10ee9bca66