FB: Heads Up background color && transparency [2/2]

PS: manual rebase

PS: fix heads up TRDS background resources

PS: clear content holder background prior to setting TRDS
        drawable so that correct drawable for TRDS state
        is set

PS: revert non-TRDS background to AOSP gray (default
        system notification background color)

PS: clean up some unused code

PS: add capability to set custom heads up text color

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java

Signed-off-by: dragon <dragon7780@hotmail.nl>