Minor improvements on FrameworksMockingServicesTests:

- Abstract common mock expectations.
- Add more logging.
- Use constants.
- Remove redundant MockitoAnnotations.initMocks() call (it was
  already initialized by ExtendedMockitoRule).

Test: atest FrameworksMockingServicesTests:UserManagerServiceMockedTest
Bug: 407838236
Flag: TEST_ONLY

Change-Id: Iec665f326bf28707714aaceaed38cd5240e4855c