Kathy Baker (The Ranch) and Heroes alum Greg Grunberg have been cast in lead roles opposite Al Pacino in HBO Films' untitled movie about the Penn State sexual abuse scandal, directed and executive produced by Barry Levinson. Written by Debora Cahn, John C. Richards and David McKenna, the film centers on legendary coach Joe Paterno (Pacino), who, after becoming the winningest coach in college football history, is embroiled in Penn State's Jerry Sandusky sexual abuse…