am a48dc39b: Add hangupForegroundResumeBackground().

Merge commit 'a48dc39bd55c5ddcd991e08f791fd18d94a0db12' into gingerbread-plus-aosp

* commit 'a48dc39bd55c5ddcd991e08f791fd18d94a0db12':
  Add hangupForegroundResumeBackground().