Clean up in-call vibration implementation.

Change-Id: Ic91e8be169f7ba62ea2dc83dee2215df8a59c915
Set ringtone mode even if ringer is silent.

We need this as we want to attenuate music players even on silent
ringtone, to make the user aware the ringer is playing.

Change-Id: I8784f95996a70ac83fcb2d45231f0c3c209bb4e1
Remove incall background