So what does it have to do with your problem?
Gear VR is hardware locked to Samsung phones: http://www.samsung.com/us/mobile/wearable-tech/SM-R322NZWAXAR
Gear VR will not work with any other phone. It has nothing to do with UE4 or the fact that UE4 has Oculus SDK. Oculus SDK provides functionality / interface for Oculus supported devices, which are Rift and Gear VR.
UE4 had a project to run it on Google Cardboard, but performance was abysmal. Search for it on the forum here.