No additional MipMaps Generated on UI Texture Group

In previous versions of the engine (4.21), 10 MipMaps are generated with the above repro steps. Starting from 4.22 and CLs above the editor only produces 1 MipMap with the above texture settings.

Tested in 4.21.2 (CL - 4753647), 4.22 (CL - 5365847), 4.23 (CL - 5408081)

1. Import a texture with the power of two resolution
2. Set the Compression Setting to User Interface RGBA
3. Make sure the Mip Gen Settings are set to FromTextureGroup
4. Change the Texture Group to UI

Expected: Multiple MipMaps are created

Result: There is only one MipMap generated