This year’s legislative battle over immigration seemed to come to a draw when Gov. Jerry Brown signed one key bill but vetoed another. Immigration rights advocates, however, said Monday that the political give-and-take was largely an illusion. They lost. The bill that Brown signed, which lets some young immigrants have driver’s licenses, allows nothing beyond what is permitted under a new federal program granting a two-year reprieve from deportation. But the bill that Brown vetoed — the Trust Act — was among the most closely watched pieces of immigration legislation in the country. It would have barred local law enforcement officials from cooperating with federal authorities in detaining suspected illegal immigrants, except in the cases of serious or violent crime.