After a veteran officer — also head of their police union — shot and killed a 20-year-old unarmed Black motorist named Daunte Wright during a traffic stop over expired tags and a dangling air freshener, you might think cops in Brooklyn Center, Minnesota, would have at least a brief moment of reflection, even contrition. Yeah, right. Instead, officers in the Minneapolis suburb — just 10 miles or so from the corner where Derek Chauvin kneeled on the neck of a dying George Floyd, sparking an American racial reckoning that apparently wasn’t — raised a version of the “thin blue line” flag over thei…