InCallUI: Add transparency to Glowpad background [1/3]

this adds transparency to the glowpad view background so the incoming caller's entire picture can be seen.
PS8:making it a preference.

PS16: Permissions

Change-Id: I33bfdc6ed641770a4e0ceb7841e0908581256757

Conflicts:
	res/values/colors.xml
	src/com/android/incallui/CallButtonFragment.java
InCallUI: Add "Answer Via Speakerphone" Glowpad Target

Change-Id: If8bdb14f1df386272c9b16816175322ecda2fa90

Conflicts:
	res/values/dimens.xml