Flip to mute/dismiss call

This patch is based on http://review.cyanogenmod.org/#/c/29894/11
to provide easy mute and dismiss functionality for the phone application.

Available actions:

0: no action
1: mute ringer
2: dismiss call

Patchset 2:
- small correction

Change-Id: I1895a1ce985a2f393ea890fd13531310af611498