In-Call UI from blue to white

we changed the default dialpad from blue to white
but forgot this in call dialpad,
make it white ui to be consistent

Change-Id: Ie715340d69adb1514e5f1d5bb159b8c42494015a
trds: cleanup!

drawables not needed anymore after this
https://gerrit.slimroms.net/#/c/1675/

Change-Id: Ic237384fe60f23dd2b953da5d7be36c9a4c1191d