Dwayne 'The Rock' Johnson is a snitch, or at least that's the basic conceit behind stuntman-turned-director Ric Roman Waugh's 'Snitch.' Johnson plays a father who agrees to go undercover into a drug cartel after the DEA busts his kid. Shaping up to be a big year for The People's Champion. He's got 'Snitch,' 'Pain & Gain,' 'The Fast and the Furious 6,' and 'G.I. Joe: Retaliation' all dropping…