[Role Logic Move] Lift user from RoleControllerServiceImpl

This change modifies RoleControllerServiceImpl, replacing all
calls to Process.myUserHandle() with an mUser variable. Also, calls to
RoleManager are called with a user-context.

After this change, we're now in a state where all of role-controller
(and RoleControllerServiceImpl) have a single UserHandle object which
is injected throughout the object hierarchy.

Bug: 302563690
Test: atest CtsRoleTestCases
Change-Id: I8112f89693d131ae99756d2ab8334d9e8cfb8b85