Repro steps:
1. Open attached project
2. Download ARCore Extension package from https://github.com/google-ar/arcore-unity-extensions/releases/ and add it in the Package Manager
3. Build and Run on Android
4. Press the buttons on the screen to change the target frame rate
5. Try putting the app in the background and resuming or locking/unlocking the device if it doesn't repro

Actual: The reported frame rate is only 2/3rds of the target

Reproducible with: 2020.1.17f1, 2020.2.0b13
Not reproducible with: 2021.1.0a1, 2021.1.0a9

Tested and reproduced on:
VLNQA00319, Google Pixel 4 Android 10.0.0, CPU: Snapdragon 855, GPU: Adreno 640

Notes:
- Couldn't build the project on 2019.4/2018.4