Hide UserSwitchTransitionView if it is not hidden within timeout.

This prevents being stuck in the Loading screen even if the proper
User Lifecycle event was not broadcast.

Test: Unit Tests + Manual -- Verify that the UserSwitchTransitionView is
hidden after the timeout threshold when the UserLifecycleEvent listener
is not registered.
Bug: 158705895

Change-Id: I895f04bda395bac271b01fbb414a8bf484348324