This method will return the current proceedTo that the RunLevelController
is working on, or it will return null if the controller is not currently
moving up or down
Services set to have a non-validating run level mode will be
activated by their associated run level service or through
injection into another service.
Services set to have a validating run level mode will be activated
and deactivated by their associated run level service but may also
be activated through injection into another service.