IntelliJ constantly inserts a * import despite all efforts to turn it off.
import java.util.*
fun String.toUUID(): UUID = UUID.fromString(this)
It turns out that it is super simple. Just turn on the single name import and delete all the packages in the now empty oval below.
It took me days of repeated attempts after getting a macbook refresh and we had team members that needed to hand edit files outside of IntelliJ before check-in. I think the confusion is that it appears to not be related to the Java import settings which most(all?) search results point to.