FALLS CHURCH, Va. — A federal judge on Friday tossed out involuntary manslaughter charges against two U.S. Park Police officers who fatally shot an unarmed motorist in northern Virginia four years ago. U.S. District Judge Claude Hilton issued an opinion declaring the actions of officers Lucas Vinyard and Alejandro Amaya “necessary and proper” in the shooting of 25-year-old Bijan Ghaisar …