LOS ANGELES (AP) - Gov. Arnold Schwarzenegger made a surprise cameo in the city's mayoral race Thursday, lining up behind a controversial proposal by candidate Bob Hertzberg to dismantle the huge Los Angeles Unified School District. The popular governor, who lives in the city's Brentwood section, has said he will not endorse a candidate before the March 8 primary election. But Schwarzenegger, by embracing Hertzberg's signature issue, appears to be sending a tacit signal of his preference without taking the political risk of a formal endorsement in a crowded field. The Republican governor is backing Hertzberg's plan because he "supports...