China is stepping up censorship of U.S. films as producers make movies with an eye toward pleasing Beijing yet without isolating the global audience, industry insiders say.     The roughly 25-year-old practice of cutting scenes that don’t conform to Communist Party ideals from Hollywood movies has expanded.   “Now it’s kind of escalated in the sense that they’re much more direct in banning films outright rather than just tampering or asking for scenes to be removed,” said Stanley Rosen, a University of Southern California political science professor who follows China’s film industry.   …