Refactor now resolved classes away from getCurrentUser()

These refactors are almost without logic changes since the parent CLs
have resolved the dependency cycles that were previously occuring

Test: Refactored tests
Bug: b/303808405
Flag: b/305984787 - REFACTOR_GETCURRENTUSER (added in ag/25089323)
Change-Id: If7de1bc183f861d06b427d1005f64cbb1a046628