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

This change modifies the following methods:

- Permissions::setPermissionFlags[AsUser]
- Permissions::setPermissionGrantedByRole[AsUser]

...by making them multi-user aware. I.e., lift any references to
Process.myUserHandle() out of them into method arguments, and call
user-dependent APIs with a user context.

Bug: 302563690
Test: atest CtsRoleTestCases
Change-Id: I712298c221d0279a3e8dee13974a03b3eb8b121c