WASHINGTON (Reuters) – U.S. Defense Secretary Lloyd Austin’s aide asked for the ambulance picking up the Pentagon chief to keep its lights and sirens off during a New Year’s Day call to 911, according to audio of call obtained by Reuters. “Can the ambulance not show up with lights and sirens? We’re trying to remain a little subtle,” the aide, whose name was redacted from the audio, told the 911 dispatcher. Austin’s trip to Walter Reed National Military Medical Center and subsequent hospitalization was kept secret for days, including from U.S. President Joe Biden and even Austin’s deputy, Kathl…