It's kinda make sense that the military would want to use homegrown product (in this case, samsung) so they can fully control what's running. They seem to want a fully locked down device, with wifi, usb, tethering, mic and camera disabled while in premise.

The reason is purportedly because iPhones do not fully comply with the restrictions outlined by the National Defence Mobile Security, a mobile device management application operated by the military authorities.

For instance, when activating the security app, it begins to restrict several smartphone functions, including the camera, Wi-Fi, tethering, USB functions and the microphone.

However, Apple does not allow third-party apps to control iPhones’ inherent features, except for the camera.