Reproduction steps:
1. Download and open the submitted project "VideoPlayer_Bug_Report.zip"
2. Build and run for Android
3. Press Prepare

Expected result: No audio is played
Actual result: a first few frames of the Video Player's audio is played

Reproducible with: 2018.4.32f1, 2019.4.13f1, 2019.4.21f1, 2020.2.6f1, 2021.1.0b8, 2021.2.0a6
Not reproducible with: 2019.4.12f1

Reproduced on:
VLNQA00122, Samsung Galaxy S9 (SM-G960F), Android 10, CPU: NOT FOUND, GPU: Mali-G72
VLNQA00285, Samsung Galaxy J4 Core (SM-J410F), Android 8.1.0, CPU: Snapdragon 425 MSM8917, GPU: Adreno (TM) 308
VLNQA00321, Xiaomi MI 9 (MI 9), Android 10, CPU: Snapdragon 855 SM8150, GPU: Adreno (TM) 640

Does not reproduce on:
iPhone 12 Pro (iOS 14.2.1)

Notes:
The issue is only reproducible when the audio output mode is set to Audio Source
On Unity 2018.4 the issue is reproducible in the Editor as well.