Writer-director David Ayer really likes cop-themed movies. He’s done all kinds of them, from frivolous fun ones ("S.W.A.T") to police corruption (“Street Kings,” “Dark Blue,” “Training Day”) ones. These have all been riveting in their own way and “End of Watch” is no exception, but this is fairly new territory in that it breaks down the brotherhood of cops. Jake Gyllenhaal and Michael Pena play Brian and Mike, South