ARKit portrait image aspect ratio incorrect on iPhone 6s,7, probably all phones.

As described in this UDN thread, the iPhone 7 manifests incorrect image aspect ratio
https://udn.unrealengine.com/questions/403841/ios-arkit-portrait-mode-stretching-on-iphone-7.html

[Link Removed] tried to repro the bug on an iPhone6s and found a repro. Also encountered crashes when switching between portrait and landscape.

Repro steps copied from https://udn.unrealengine.com/questions/403841/ios-arkit-portrait-mode-stretching-on-iphone-7.html

1. Create a new blank C++ project for Mobile / Tablet with Scalable 3D or 2D
2. Create an empty level
3. Add an empty pawn to the scene at (0,0,0), and add a camera component to it
4. Set the pawn to Auto Possess Player 0
5. In the Project Settings, set the game default map to your newly created level
6. Set Start in AR to true
7. In IOS settings, setup your development certifcates / provisions / bundle info
8. In IOS, set orientation to Supports Portrait Orientation only
9. In IOS, set Metal standard to Metal v 1.2(iOS 10.0/tvOS 10.0)
10. Set minimum IOS level to 11.0
11. Set framerate lock to 60 fps
12. Setup remote build options (if building from Windows to a remote mac, which I am)
13. Package project and deploy to iPhone 7
14. Observe incorrect launch image and stretched camera feed