[Role Logic Move] Make NotificationUtils user-aware

This change modifies all methods in NotificationUtils, by
making them multi-user aware. I.e., lift any references to
Process.myUserHandle() out of them into method arguments.

Bug: 302563690
Test: atest CtsRoleTestCases
Change-Id: I286dec5fb1f323bdd2552cf13f667d4fdee84f7a