From coach life to proud dad life. Mike Tomlin made his first public appearance since stepping down as the Steelers’ coach on Tuesday to attend daughter Harley’s college gymnastics meet Friday night. Tomlin, 53, sported a Georgia sweatshirt while watching his daughter’s eighth-ranked squad edge No. 2 LSU at Stegeman Coliseum in Athens, Ga. Harley, a sophomore, competed in the balance beam and floor exercise segments. That Tomlin traveled south just days after his shocking exit from the Steelers