SAN FRANCISCO (Reuters) - A U.S. Supreme Court ruling backing Oregon's physician-assisted suicide law gives a major boost to a similar measure languishing in the California legislature since last year, lawmakers said on Tuesday. "I believe we will get this bill passed this year and signed by the governor," said Assemblyman Lloyd Levine, co-author of a law to allow state residents to obtain lethal medication if they had less than six months to live. Levine, a Democrat, spoke after the U.S. Supreme Court rejected legal arguments by the Bush Administration seeking to strike down Oregon's pioneering Death with Dignity Act....