Reproduction steps:
1. Create a New Project
2. Import a Managed .dll file
3. Add a Constraint (e.x. "UNITY_EDITOR")
4. Click "Apply"
5. Select another asset
6. See a pop-up "Unapplied import settings"
7. "Apply"
8. Re-select the .dll
9. Notice that no Constraints are defined

Expected Result: Import Settings applies settings when "Apply" is pressed
Actual Result: "Unapplied import settings" always pops-up, even when saved/"Apply" doesn't save the asset import settings

Reproduced with: 2020.1.0a4, 2019.3.0b3, 2019.3.0a10, 2019.3.0a9, 2019.3.0a8
Did not reproduce on: 2019.3.0a7, 2019.3.0a5, 2019.3.0a1, 2019.2, 2019.1, 2018.4, 2017.4