If the Golden State Warriors fend off the Oklahoma City Thunder on Saturday and bring a showdown Game 7 of the NBA Western Conference Finals to Oakland's Oracle Arena Monday night, perhaps no one will be happier than the sellers of counterfeit merchandise. Then again, maybe not. Street-level vendors of unlicensed National Basketball Association hats, jerseys, T-shirts and more — as well as San Jose Sharks lookalike apparel during the Stanley Cup Finals — stand to rake in thousands of dollars.…