July 6 (Reuters) - President Donald Trump said on Monday that Walmart would lower prices on many products, including ground beef, after a request from his administration. The retailer said customers would save on items including meat, produce and soda at its Walmart and Sam's Club stores this summer. Record-high beef prices have strained the wallets of U.S. consumers who also paid much higher gasoline prices after the U.S. and Israel launched attacks on Iran in February. Prices for steaks and hamburger meat soared after a persistent drought burned pasture lands and hiked costs of cattle feed, forcing U.S. ranchers...