How to reproduce:
1. Open the attached "1253197 repro" project
2. Open the Package Manager window from Window > Package Manager
3. Select "SimplePackage" Package
4. Open the "manifest.json file" from 1253197 repro > Packages
5. Change the location folder of the "com.augustinas.simple-test" package from "MyCustomPackages" to "MyCustomPackages2" and save
6. Return to the Unity Editor

Expected result: the Package Manager window shows an updated PackageInfo.resolvedPath
Actual result: the Package Manager window show an old PackageInfo.resolvedPath

Reproducible with: 2019.4.0f1, 2020.1.0a23
Not reproducible with: 2020.1.0a24, 2020.1.0b12, 2020.2.0a15
Could not test with: 2018.4.23f1 (IPackageManagerExtension doesn't exist)

Notes:
-The PackageInfo is updated if any of the Scripts in the project are recompiled
-The PackageInfo is updated if the content of "package.json" changes. This can be observed by using "MyCustomPackages3" instead of "MyCustomPackages2" in the 5th step
-The PackageInfo doesn't update when changing the package's location from Registry to Local and therefore old PackageInfo.registry and PackageInfo.source are shown