Reproduction steps:
1. Open the attached project
2. Select aa.rc.json file in the Project Window
3. At the top of the inspector, click on the Importer dropdown.
Expected result: “SomeImporter” is the (Default)
Actual result: “TextScriptImporter” is set as (Default)
Reproducible with: 2022.1.9f1, 2022.2.0b1, 2023.1.0a3
Could not test with: 2020.3.37f1, 2021.3.6f1: Error “The scripted importer 'SomeImporter' attempted to register file type '.rc.json', which is handled by a native Unity importer. Registration rejected.
UnityEditor.AssetImporters.ScriptedImporter:RegisterScriptedImporters ()”
Reproducible on: Windows 10