Kathleen Brown, the daughter of one Governor and the sister of another, won a solid victory in California's Democratic gubernatorial primary. Sitting GOP Governor Pete Wilson won his own party's nomination handily, but he faces a tough run for another seat. If the election were held today, say the pollsters, Brown would unseat the implacable Wilson. Eight other states held primaries yesterday. The most notable: Fred Grandy, who overcame his reputation as the clownish "Gopher" on "The Love Boat" to win a seat in Congress, lost his bid for the governorship of Iowa.