Variety: NBC has canceled “A.D.: The Bible Continues” after one season, but producers Mark Burnett and Roma Downey plan to return to the greatest story ever told on their nascent digital channel. Now that the “A.D.” moniker is established with a devoted cadre of viewers, Burnett and Downey see it as a perfect tentpole for the launch of the OTT channel they have been working on since partnering with MGM to form United Artists Media Group last fall.