Full video airs Friday night on '20/20.'By Jocelyn Vena Rihanna Photo: Ray Tamarra/Getty Images Rihanna's music video for "Russian Roulette" doesn't premiere until Friday night on "20/20," but the singer did release a snippet of the Anthony Mandler-directed clip on a German talk show. On Wednesday when the singer, who drops her Rated R album on November 23, stopped by "TV Total" in Germany to chat about her new album, she also previewed about 30 seconds of the video.