By Sarah El Safty and Maha El DahanDUBAI, March 5 (Reuters) - Wealthy Gulf states are facing their biggest food security challenge since the 2008 global food crisis, as the Iran conflict threatens ports and disrupts shipping through the Strait of Hormuz.The war is testing strategies adopted after 2008, when soaring food prices prompted Gulf nations to shift toward import-dependent policies reliant on pouring cash into agricultural investments abroad.