Limit when a ranking reconsidering can alert

Otherwise notifications that were silenced by DND that
still exist when DND is turned off can re-alert.

Test: StatusBarTest,  "with zen". No alerts should happen
within ~10 seconds of starting the test
Change-Id: I9e58118c0a40e0d4f1bafb0913e569b560879ba2
Fixes: 62355996