ATLANTA — Atlanta Hawks co-owner Bruce Levenson says he had “dozens” of conversations with Danny Ferry over three months as the two discussed what it would take for Ferry to leave the San Antonio Spurs. Levenson’s persistence paid off Monday as Ferry was introduced as the Hawks’ president of basketball operations and general manager. Levenson said Ferry, 45, was the only candidate he interviewed after Rick Sund, who had been general manager for four years, suggested three months ago it was time to look for new long-term leadership for the team.