By Matt Audilet The final years of Bill Cowher’s coaching career with the Steelers ushered in a new era of Pittsburgh football. In 2004, Cowher and the Steelers organization selected quarterback Ben Roethlisberger with the No. 11 overall pick in the draft. And for the next three seasons, the veteran head coach worked closely alongside the talented young signal caller. Now 18 years after Big Ben suited up for his first Steelers game, the 39-year-old quarterback has officially announced his retirement decision. Cowher, who now works as an analyst for CBS Sports, shared a message celebrating Roet…