GLENDALE, Ariz. — In his first game in an Oakland Raider uniform, Marshawn Lynch didn’t play a down. Yet he provided the most vivid image of the night, sitting for the national anthem before the Raiders’ 20-10 preseason loss to the Arizona Cardinals on Saturday. The ex-Seattle running back, who came out of retirement to sign with his hometown Raiders, sat on an orange cooler with his arms resting on his knees, while others around him stood. Although he rarely talks to the media, Lynch has voiced support for quarterback Colin Kaepernick’s decision to kneel during the anthem last season to protest what he saw as a pattern of police mistreatment of…