Dwayne Johnson’s stage name, The Rock, was first crafted in the gladiatorial arenas of the World Wrestling Entertainment and then adopted for his various on-screen projects. For years, his physique mirrored this name; everything about him was huge, strong and seemingly ageless. No wonder Disney cast him as the voice of a demigod in “Moana.” He practically is one in real life. All of this made Johnson’s appearance on the film festival circuit in September to promote his artsy new movie “The