allow forcing HighEndGfx mode

people have already started fipping the lomRam prop to enable
transparent status bar, this will enable it with fewer
repercussions

Change-Id: Ied6de65276425fa1e7db0bf9da35f1932a355172
Keyguard: enable widgets on lowram devices

Change-Id: Icf5d6982b4729153ddeb26e9fbb648392bb96e66