Movie stars at the top of their game can often feel invincible, but there was something about Dwayne Johnson’s 2000s climb from wrestler to bankable Hollywood star that seemed uniquely bulletproof. Possessing an endless supply of charm and an aggressive careerist streak, “The Rock” seemed to will his way to the top of the wrestling world and then the box office, managing the tricky maneuver of being ever-present — on the big screen, in random TV appearances, on Instagram — yet not suffocating.