frameworks/native: Add support for Secure Display.

- Add secure UI layers to primary and remove other layers from
  internal and external list for Secure Display usecase.
- Dont let secure UI layers to be captured on screen

Change-Id: Iebdad5c56247308604ee90928f6d6460a1f69279
Merge remote-tracking branch 'CyanogenMod/cm-10.2' into cm-10.2