DocumentsUI: fix white action context bar in TRDS tablet view

Change-Id: I3c580a2aa4f8abbcfd06ad974518343f6e9190c5
Base: fix some compiler warnings

Change-Id: Ifb609ca1091edd92cfb414dfc8c3c501d3e38a9d
FB: Heads Up background color && transparency [2/2]

PS: manual rebase

PS: fix my retardedness

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
Change-Id: I3942c0ce178491e3429e5ae7eb24b43ba07a1f40
Merge remote-tracking branch 'upstream/kk4.4' into kk4.4-mo4