“Import” buttons incorrectly change to “Reimport” for non-imported Samples after importing multiple Samples from “All Samples” section

Steps to reproduce:

1. Create new Unity project using Universal 3D Template
2. Open Package Manager window
3. Select “All Samples” section
4. Scroll down through the list
5. Import these samples: “URP RenderGraph Samples, “URP Package Samples”, “Render Shader User Value Samples”
6. After importing these samples, select any other Sample
7. Observe “Import” button

Actual results: After importing multiple samples (e.g., "URP RenderGraph Samples," "URP Package Samples," "Render Shader User Value Samples") from the "All Samples" section, selecting any other sample that has not been imported shows a "Reimport" button instead of an "Import" button, incorrectly indicating the sample has already been imported

Expected results: Samples that have not been imported should continue to display the "Import" button regardless of how many other samples have been imported to the project, only previously imported samples should show the "Reimport" button

Reproducible with versions: 6000.6.0a6 (5c9528587bc8)

Not reproducible with versions: 6000.6.0a5 (e220e6931c38)

Tested on (OS): macOS Tahoe 26.4.1 (M1), Ubuntu 24.04

Notes:

• Issue is possible triggered by “Render Shader User Value Samples” 
• Sometimes it might require to import “Timeline Gameplay Sequence Demo” and “Timeline Customization Demo” Samples
• Pressing "Reimport" button in previously not imported Samples does nothing
• Error does not reproduce with multi-import