Improved audio focus handling for CARSM

Eliminates the REINITIALIZE message, which was originally written for
compatiblity with the old CallAudioManager. Resetting the audio route
back to the default state now occurs automatically whenever we lose
audio focus.

Also adds logging session support to InCallTonePlayer

Bug: 27555048
Change-Id: I4b7bb6c81aa2a38670fd3768dd65d4b3e24841eb