A railroad, sleeping car, dining car, boat, or steamship company or air common carrier carrying interstate or foreign passengers on trains, boats, or airplanes shall not be deemed to be an importer or subject to an importer’s license for bringing into this State alcoholic beverages for the purpose of sale within this State on the trains, cars, boats, or airplanes on which the alcoholic beverages are brought into this State exclusively to passengers or employees not on duty, and for carrying the same alcoholic beverages or any unsold portion thereof out of this State in due course of operation.