Add white list heads up

Huge thanks to CyanogenMod

HeadsUpManager and HeadsUpAppListAdapter are copies of the PrivacyGuardManager and PrivacyGuardAppListAdapter edited to make them work with HeadsUp

Change-Id: I782ae4f7156574147d145858b86d1c8e2c7cd0d9
Merge "Add white list heads up" into pac-4.4