To reproduce:

1. Download and open attached "Test.zip" project.
2. Find a device which supports split screen.
3. Open any application which supports split screen.
4. Go into split screen mode.
5. Build and run provided Test application on the device.
6. Exit split screen mode by dragging the screen divider so that the test app fills the screen.
7. Observe that screen orientation changes even though the device is held fixed.

Expected result: Screen orientation does not change when exiting split screen.
Actual result: Screen orientation changes when split screen is exited. On some devices screen does not stop rotating even though the device is stationary.

Reproduced with: 2018.1.0a2, 2017.3.0b7, 2017.2.0p1, 2017.1.2p2, 5.6.4p1, 5.5.5p1.

Google Pixel XL*, OS:8.0.0, CPU:arm64-v8a, GPU:Adreno (TM) 530,
Build:google/marlin/marlin:O/OPP2.170420.019/4021594:user/release-keys

HUAWEI EVA L19*, OS:7.0, CPU:arm64-v8a, GPU:Mali-T880,
Build:HUAWEI/EVA-L19/HWEVA:7.0/HUAWEIEVA-L19/C432B386:user/release-keys

Samsung SM G950U*, OS:7.0, CPU:arm64-v8a, GPU:Adreno (TM) 540,
Build:samsung/dreamqltesq/dreamqltesq:7.0/NRD90M/G950USQU1AQC8:user/release-keys

Notes: Did not reproduce on iPad Air 2 iOS 9.2.

Verified with: 2018.2