The title of the 1970 documentary That's The Way It Is might have been plain-spoken, but nothing else was plain about the chronicle of Elvis Presley's return to the concert stage. And there's certainly nothing plain about the extravagant treatment being accorded the film and its companion album this summer. Why, we'd even say it's fit for a - make that, The King. On August 5, Legacy Recordings will team with Warner Bros. Home Video for a massive 8-CD/2-DVD box set including six full-length