How to reproduce:
1. Open the attached project
2. Set iOS as build target
3. In Player settings, set camera usage description
4. Build the project for iOS
5. Build & Run to device via Xcode
6. Press "Game"
7. Press "MainMenu"
8. Repeat steps 6-7

Actual result: Unity leaks memory.
Expected result: Unity doesn't leak memory.

Reproducible with: 2019.2.20f1 (2.0.2), 2019.3.1f1 (3.1.0), 2020.1.0a23 (3.1.0).

Devices reproducible with:
- iPhone 8 Plus (iOS 12.0)
- iPhone X (iOS 11.3.1)
- iPhone 6S (iOS 13.3.1)
- VLNQA00230, Oneplus OnePlus6T (ONEPLUS A6013), Android 9, CPU: Snapdragon 845 SDM845, GPU: Adreno (TM) 630
- VLNQA00277, Asus ROG Phone (ASUS_Z01QD), Android 8.1.0, CPU: Snapdragon 845 SDM845, GPU: Adreno (TM) 630
- VLNQA00315, Samsung Galaxy Note10 (SM-N970U), Android 9, CPU: Snapdragon 855 SM8150, GPU: Adreno (TM) 640

Notes:
- The leak is 10 times bigger on iOS 13 devices.
- Unity's memory profiler is not detecting the leak.
- In 2019.2.20f1 (AR F 2.0.2) the leak is a lot smaller but the leak is still visible.
- Can't test 2018.4 as the project breaks.