App UI Shaders are automatically added to the Preloaded Shaders list when adding or reimporting the AppUI package

Reproduction steps:
1. Open the attached “BugRepro” project
2. Open the Graphics window (Edit > Project Settings > Graphics)
3. In the Preloaded Shaders section remove the App UI Shaders by setting the Size field to 0
4. Go to the Packages folder in the Project window and reimport the App UI package (right-click > reimport)
5. Check the Preloaded Shaders section

Expected result: App UI Shaders are not added to the list
Actual result: App UI Shaders are added again to the list automatically

Reproducible with: 1.1.0, 2.0.0-pre.8 (2021.3.44f1, 2022.3.50f1, 6000.0.22f1)

Reproducible on: Windows 11
Not reproducible on: No other environment tested