Make some Sprite Atlas Variant settings Platform specific

When we create a Master sprite atlas, we have the option to create a Variant. Unity's docs say:

"Create multiple Variant Atlases with the same Master Atlas and different Scale values to create lower-resolution copies of the Atlas Texture. This is useful if you want to create various Variant Atlases for a range of platforms with different hardware limitations."

This would be true, if the Scaling and "Include in Build" options were tied to the platform-specific tabs, but they are not...

Make some Sprite Atlas Variant settings Platform specific