DC's upcoming Dynamic Duo movie now has Dick Grayson. It has Jason Todd.  It has members of the Red Hood Gang. It has a new release date. But there is one rather conspicuous absence. Batman. The animated feature has confirmed Mason Thames as Dick Grayson and Logan Kim as Jason Todd, giving DC two Robins for one of its most unusual upcoming Batman-related projects. Bruce Wayne, however, has not yet been officially cast.   Two Robins, one very different origin Dynamic Duo is not simply retelling the familiar comic-book histories of Dick and Jason. The movie will depict them as childhood friends and fellow