Make grant dialog inherit in-front-of-lock-screen

Only show permission grant dialogs in front of lock screen if calling
app is also in front of lock screen.

Test: 1. Clear storage of camera app
      2. Open camera -> permission grant dialog will pop up
      3. Turn screen off
      4. Turn screen on -> grant dialog is _behind_ lock screen
Fixes: 109754623
Change-Id: I9eab9ba27211621db02794a19fab49b5eac49a71