am c1a564b1: Merge "Add support for secure system overlays.  (DO NOT MERGE)" into gingerbread

Merge commit 'c1a564b108c511c0bdd699567c245b031930e718' into gingerbread-plus-aosp

* commit 'c1a564b108c511c0bdd699567c245b031930e718':
  Add support for secure system overlays.  (DO NOT MERGE)