Over the past week, one conversation has dominated Hollywood executive lunches and studio staff meetings: What's the next "Backrooms"? The industry is scrambling to figure out how to replicate the phenomenon of "Obsession" and "Backrooms," low-budget psychological horror films directed by YouTube creators that have dominated the box office over the past two weeks. But "Backrooms" producer Peter Chernin, whose production company cofinanced the film, said he thinks the rush to sign deals with