P.O.R.N PS6

* Make sure a call is not in progress when using pocket mode
  to turn the screen.
* Include option for displaying ongoing and non-clearable
  notifications.

Change-Id: I22d65faf9bb226cc95b7eebd8e18ca872d18149f
Signed-off-by: iGio90 <giovanni.rocca.90@gmail.com>