How to reproduce:
1. Open the attached "VideoTest.zip" project
2. Switch platform to Android
3. Go to Player Settings -> Player -> Other Settings -> enable "Multithreaded Rendering"
4. Build & run the project on Android

Expected result: No issues
Actual result: Video is shuttering and freezes every 2 seconds

Reproducible in: 5.6.3f1, 2018.4.11f1, 2019.3.5f1

Reproducible with:
RedMi 1s
Samsung Tab A6 (information from users)
Kindle Fire 5th Gen (information from users)
Samsung Galaxy S5e (information from users)

Not reproducible:
Samsung Galaxy S3 (information from users)
VLNQA00269, Samsung Galaxy S10e (SM-G970F), Android 9, CPU: Exynos 9 9820, GPU: Mali-G76
VLNQA00090, Samsung Galaxy S8 (SM-G950U), Android 7.0, CPU: Snapdragon 835 MSM8998, GPU: Adreno (TM) 540
VLNQA00119, Xiaomi Mi 5 (MI 5), Android 8.0.0, CPU: Snapdragon 820 MSM8996, GPU: Adreno (TM) 530
VLNQA00216, Razer Phone 2 (Phone 2), Android 8.1.0, CPU: Snapdragon 845 SDM845, GPU: Adreno (TM) 630
VLNQA00287, Motorola moto g(7) power (moto g(7) power), Android 9, CPU: Snapdragon 625 MSM8953, GPU: Adreno (TM) 506
VLNQA00031, Lge Nexus 5 (Nexus 5), Android 6.0.1, CPU: Snapdragon 800 MSM8974, GPU: Adreno (TM) 330
VLNQA00111, Samsung Galaxy J5(2016) (SM-J510FN), Android 7.1.1, CPU: Snapdragon 410 MSM8916, GPU: Adreno (TM) 306
VLNQA00251, Amazon UNKNOWN (KFDOWI), Android 5.1.1, CPU: MediaTek MT8163, GPU: Mali-T720
VLNQA00092, Samsung Galaxy Tab4 10.1 (SM-T533), Android 5.1.1, CPU: Snapdragon 410 MSM8916, GPU: Adreno (TM) 306
VLNQA00035, Motorola DROID MAXX 2 (XT1021), Android 4.4.4, CPU: NOT FOUND, GPU: Adreno (TM) 305

Notes:
- MP4 videos settings:
Override for Android - marked
Transcode - marked
Codec H264
Bitrate Mode High
Spatial Quality High Spatial Quality