Reproduction Steps:
1. Open "Camera" project
2. Build for iOS
3. Check if orientation is locked to Landscape Right only
4. In Xcode add Camera Privacy
5. Build and deploy to iOS device
6. Press GUI Button
Note: Camera app should open
7. Hold device in portrait orientation
8. Press Home Button to bring app to the background
9. Press Home button twice and select this app
10. Orientation is changed to portrait rotation and locked

Expected behaviour: Built app with locked orientations cannot be rotated or is rotated back to its locked rotation.
Actual result: If closed on portrait camera app is locked in wrong orientation.

Reproduced on versions: Unity 5.4.4p3, 5.5.0p4 5.6.0b7
Could not reproduced on: Unity 5.5.1.p3 (camera is not closed automatically after coming back, therefore, bug does not reproduce)
Reproduced on devices: iPhone 6 iOS 10.2.1, iPhone 6 Plus iOS 10.1