Animations attributes get corrupted in the Animation window when opening the project in a newer version of Unity

To reproduce:
1. Open the project “TestCam2021” in Unity 2019.3 or 2020.3
2. Open the Animation window (Window → Animation → Animation)
3. Assets → Art, expand TestCam2021
4. Select any of the three animations and notice their Camera.Focal length attribute in the Animation window
5. Open the project in Unity 2021.2.0a17 or above
6. Select any of the three animations (Assets → Art → TestCam2021)

Expected result: The attributes were not changed
Actual result: One attribute was added to the first animation and one attribute was removed from the other two

Reproducible with: 2021.2.0a17, 2021.3.8f1, 2022.1.13f1, 2022.2.0b4, 2023.1.0a6
Not reproducible with: 2020.3.38f1, 2021.2.0a16

Reproduced on: macOS Monterey 12.5.1 (Intel)