[Notif] Don't show bouncer on dismiss

For blocking helper, when user dismisses by interacting with elements
outside the current notification, we should not show the bouncer.

Changed the logic to only show bouncer/use the checksaverunnable when
the user hits 'stop notifications'

Test: Added test cases, ran via atest, verified manually too
Bug: 80132806
Change-Id: Ic204e1794360684cd6359ff93e77e184e39ad57e