Fix dialer bubbles not bubbling / remove alertAgain logic

I had carried this in from notification alert logic but looking at it
more closely it seems not appropriate here (maybe appropriate / something
to incorporate for the flyout?)

Dialer has a notification when the phone call comes in and then when you
leave the phone activity they update that notification to bubble, the
alertAgain logic was filtering this update out.

Test: manual with dialer APK - get a phone call, leave the phone call
      activity, note that a bubble is displayed on screen
Bug: 131252815

Change-Id: I05bff55863b5dd40037741c133eea30397c11b58