Update NotificationRecord of snooze even after it is cancelled

Symptom:
If a snoozed notification is cancelled and new notification that has
same key is registered, the system continue to snooze the
notification. But the notification won't be notified when the snoozing
period expires.

Root cause:
SnoozeHelper doesn't update NotificationRecord if the existing record
has already been cancelled. SnoozeHelper continue to use existing
cancelled record. So SnoozeHelper doesn't repost notification when the
snoozing period expires.

Solution:
SnoozeHelper updates NotificationRecord even if the existing record
has been cancelled.

Test: atest SnoozeHelperTest

Fixes: 140462813
Change-Id: I43468bf8ac712e09c288d71965dae34de439c5a8