gltfasset material loss on load

[mwfarb]

This may only affect a few gltf models, but some lose their materials on load, and it can effect other models. Load this model: https://arena-dev1.conix.io/store/users/agr/arena-scans/arena-occluder.glb.

• Load from an Editor-time GltfAsset component. (optional)
• Load from a Runtime GtTFast importer .Load() or .LoadFile().
• At Editor-time the model has the right material.
• At Runtime, the import of the same model causes both to lose their materials.

[mwfarb]

Leon might have the right thought if it's a "Unity asset reference problem, like some empty object with the same guid is imported over somehow".

[mwfarb]

There are a handful of import and instantiation settings that can be used on import, I wonder if the defaults aren’t quiet right.