Allow creating custom dialogs in DialogPreference.

This allows creating non-AlertDialogs while still using the click and
state handling of DialogPreference.

Change-Id: I54fd7d6d6b9f6a49fef1ae95e0178838b3edfa56
StatusBar: Disable mobile and wifi activity overlays

* Just never pass the real one but a null one, don't affect anything else.* Easy way instead of a MASSIVE revert
  that relays on also the half of the Chinese status bar MASSIVE patch.
  So take it easy.
* Apply to MSim too

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>