glTF2 import doesn't enable VRAM texture compression for embedded textures

[fire]

Godot version:

3.2.3 stable

OS/device including version:
win10

Issue description:

This is probably a duplicate, but I'd post it first.

Tried importing https://www.dropbox.com/s/ka378kmu62i669m/Bistro_Godot.glb?dl=0 and none of the textures were texture compressed.

Steps to reproduce:

1. Create an empty project
2. Download glb
3. open
4. double click on a material
5. click edit

Minimal reproduction project:

See reproduction steps. A zip of the project would be > 200mb.