The get_testy_service_name returns the name of the testy service based on the value of the active workload. If the current_workload value is not set in the .testy configuration, the service name is invalid. This can happen when the start or populate functions are called for the first time.

This ticket is to update the get_testy_service_name function to return an appropriate value (such as None) when the current_workload is not set in the configuration, so that the calling function can check the return value before proceeding.