Joe Otterson TV ReporterThe zombie apocalypse that took hold of TV in 2010 was very, very good for Steven Yeun.To say that “The Walking Dead” was Yeun’s breakout role would be an understatement so powerful it could reanimate a corpse.Yeun had a handful of onscreen credits to his name before he was cast in the AMC series in the role of Glenn Rhee. The character immediately proved to be pivotal to the series, as he was the one who initially rescued Andrew Lincoln’s Rick Grimes from zombies in the