Pinpointing Elvis Presley’s true persona can depend on when and whom you ask.Don Cravens/Getty Images Michael T. Bertrand, Tennessee State University In Baz Luhrmann’s “Elvis,” there’s a scene based on actual conversations that took place between Elvis Presley and Steve Binder, the director of a 1968 NBC television special that signaled the singer’s return to live performing. Binder, an iconoclast unimpressed by Presley’s recent work, had pushed Elvis to reach back into his past to revitalize a career stalled by years of mediocre movies and soundtrack albums. According to the director, their e…