am c7f25410: DO NOT MERGE Fix Activity instance leak by ContactsPreferences observer

Merge commit 'c7f25410daccf9e14c1726fd3e778910d894f243' into gingerbread-plus-aosp

* commit 'c7f25410daccf9e14c1726fd3e778910d894f243':
  DO NOT MERGE Fix Activity instance leak by ContactsPreferences observer