Steps to reproduce:
1. Open "rotationBugEmptyStripped" project
2. Build and run"SampleScene" scene on Android
3. Rotate phone from portrait to landscape and back to portrait (the more times you switch between landscape & portrait mode the more visible the bug becomes)
The screen starts flickering before fully re-adjusting screen aspect ratio to correct one after rotating (inspect the attached video)

Actual result: half of the screen flickers after rotating the device just before the scene view is readjusted correctly
Expected result: Screen should rotate without any visual artifacts no matter how many times device is rotated

Note: This can be reproduced with a new project.
Note: Not reproducible on iOS (tested with 2019.3.0a8)
Note: Reproducible on Vulkan and OpenGLES

Vulkan and OpenGLES yields a bit different results
Vulkan: After each rotation, aspect ratio takes longer to correct itself but no visual distortions or flickering are visible
OpenGLES: After each rotation, the screen is split in two and one side starts flickering for some amount of time (the more times you switch between landscape & portrait, the longer it stays in that flickering state)

Reproduced with: 2019.1.0a13, 2019.1.0a14, 2019.1.0b3, 2019.1.9f1, 2019.2.0a1, 2019.2.0b7, 2019.3.0a3, 2019.3.0a8
Doesn't reproduce with: 2017.4.29f1, 2018.4.3f1, 2019.1.0a10, 2019.1.0a12,
Regressed in: 2019.1.0a13

Couldn't test on 2019.3.0a1 & a2 because of errors

Devices under test:
Reproduced with:
1. Qualcomm (msmnile for arm64), 9, CPU: Snapdragon 855 SM8150, GPU: Adreno (TM) 640
2. Google Pixel 2 XL (Pixel 2 XL), 9, CPU: Snapdragon 835 MSM8998, GPU: Adreno (TM) 540
3. Xiaomi (POCOPHONE F1), 9, CPU: Snapdragon 845 SDM845, GPU: Adreno (TM) 630
4. Huawei (LYA-L29), 9, CPU: HiSilicon Kirin 980, GPU: Mali-G76
5. Samsung Galaxy S9 (SM-G960F), 8.0.0, CPU: Exynos 9 Series 9810, GPU: Mali-G72