CM11 Themes: Properly handle themeing apps on install

Previously when an app was installed or re-installed it would not
pick up the currently applied theme.

mOverlays was not being properly updated and therefore newly
installed or re-installed apps would not pick up the currently
applied theme.

Change-Id: I7ce5454af11fb44e9a73b30858d893050b2fba8a
CM11 Themes: Handle legacy themes in createIdmapsForPackageLI

Change-Id: Iff42bac7bf84b9c739831775c8deef86adbdc0ca
Merge changes Iff42bac7,I7ce5454a into cm-11.0

* changes:
  CM11 Themes: Handle legacy themes in createIdmapsForPackageLI
  CM11 Themes: Properly handle themeing apps on install