By David Shepardson WASHINGTON (Reuters) -The U.S. aviation regulator said on Monday it expects Boeing Co to resume deliveries of its 787 Dreamliner in coming days after the manufacturer made inspection and retrofit changes needed to meet certification standards. Boeing halted deliveries in May 2021 after the FAA raised concerns about its proposed inspection method. In September 2020, the FAA said it was investigating manufacturing flaws in some 787 jetliners. American Airlines is set to receive the first 787 airplane delivered by Boeing since the halt, sources said, and the Federal Aviation A…