[Role Logic Move] Lift user from Permissions::getAppOpMode

This change modifies the following methods:

- Permissions::getAppOpMode[AsUser]
- Permissions::setAppOpMode[AsUser]

...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: Ibe2730a3f6cf8858860c5ce44f298d01a5593add