ActiveDisplay: don't get call status while checking for valid notifications

isValidNotification(...) is called at times other than when we're checking
to see if we need to show active display so lets check for call status at that
time only

Change-Id: I59177f538cee572f9591af89d175b36530041944
ActiveDisplay: revert to keyguard if all notifications are dismissed

Change-Id: I973b9b596b4391c40734b4a0ffbb3ec0fcf31153
Fix NPE on tablets for notification navbar action

QS side doesn't ever add the button it looks for to determine shade state
because it doesnt' have "flip" settings

Change-Id: If47bb6505616b5d98f3eebf656da1435f29f7cb2