Add support for profiles in MediaRouterService

Before this change, only the currently active user is tracked
by the service's internal state. After this change, also the
profiles of the current active user are tracked.

Test: atest CtsMediaBetterTogetherTestCases
Bug: 242188673
Bug: 136703681
Change-Id: If17dad36461a5877678cd0cd0e2fceee7591a718