[2/2] Dialer: Add a non-intrusive dialoger for incoming calls

Change-Id: Ibbb9653b4a1da12fe3a7ad8f98ecbb8bffb13311
InCallUI: add decline and answer incoming call action on notifications (2/2)

Partially ported from SlimRoms
Thanks to @kufikugel

PS2: Align actions

Change-Id: I7eab5b6f4c81249613aa951fc6f01c3ed8998a93