Over the past decade, Sgt. Shane Ortega has served three combat tours: Two in Iraq, one in Afghanistan. Two as a Marine and one in the Army. Two as a woman and one as a man. Ortega is a helicopter crew chief in the Army’s 25th Infantry Division in Hawaii. He was born female and would like to serve the rest of his career as a man. That would require a significant change in Pentagon rules, which require that transgender troops be discharged from military service, usually on medical grounds. Last summer, medical tests showed Ortega had elevated testosterone levels...