United Natural Foods Inc., a grocery distributor for Amazon Inc.’s Whole Foods Market, is working to bring systems back online by June 15 and resume product deliveries after a cyberattack disrupted its operations, leaving some store shelves barren of ice cream, bread and other goods.The Providence, Rhode Island-based chain shut down IT systems and limited shipping orders after determining on June 5 that intruders had penetrated its network, Chief Executive Officer Sandy Douglas said in an earnin...