All those trendy Hollywood save-the-rain-forest, vegetarian, antifur types are about to get a rude awakening: This week Comedy Central's rambunctious chat show Politically Incorrect leaves its New York studio for L.A. for four live shows and an Academy Awards special. Among the panelists who'll be arguing about the Oscars and other topics (like whether ''secondhand television'' is as dangerous as secondhand smoke): Kelsey Grammer, Tim Allen, Ed Asner, Grant Tinker, Dick Clark, Tom Hayden, Quentin Tarantino, and the incomparable Shelley Winters. ''I insisted on getting her,'' says PI's charmingly abrasive host, stand-up comic Bill Maher. ''She's won three Oscars and was politically incorrect three decades before the term was even invented.'' Note: You can get an extra dose of Maher in his Oscar-night report for NBC's The Tonight Show.