MANILA, Philippines—The Philippines signed a 32 billion-peso ($624 million) deal Tuesday to purchase 32 Black Hawk helicopters in the largest military aircraft acquisition contract under outgoing President Rodrigo Duterte, defense officials said. Defense Secretary Delfin Lorenzana signed the deal with Janusz Zakrecki, president of Poland-based aerospace manufacturer PZL Mielec, to acquire the S-70i Black Hawks,…