GTLF importer doesn't set Root Motion to true when animation type is mecanim (non-humanoid)

### Describe the bug 💬

This behavior is inconsistent with FBX importer and requires user to apply an prefab override manually on every single model imported.

FBX Importer (!!! IMPORTANT !!!! For this to work, Root node in "Rig" tab must be assigned correctly):

UnityGLTF Importer:

### Steps to reproduce 🔢

1. Import a model with "Generic" animation type.
2. See that Root Motion is unchecked.

### Files to reproduce the issue ♻

Model files are added in the comment section.

### Editor Version 🎲

Other (Provide details below)

### Render Pipeline and version

Not relevant

### UnityGLTF Version

2.17.1

### Operating System 👩‍💻

Windows

### When does this problem happen?

- [x] Editor Import
- [ ] Runtime Import
- [ ] Editor Export
- [ ] Runtime Export

### Additional Info 📜

_No response_

### Validations 🩹

- [x] I have [searched existing issues](https://github.com/KhronosGroup/UnityGLTF/issues): no issue already exist that reports the same problem.
- [x] I follow the [Code of Conduct](https://www.khronos.org/about/code-of-conduct)
- [x] I provided a [minimal reproducible example](https://stackoverflow.com/help/minimal-reproducible-example), including files when necessary.

Reproduce the editor-import case with a model using Generic/Mecanim animation type, then trace the UnityGLTF importer path that configures Root Motion. Compare its result with the FBX importer behavior; done when imported Generic animations have Root Motion enabled without a prefab override.

Written by the indexing model from the issue text.