prevent immutable resource with static names

Kubelet has an open bug that immutable secrets/configmaps are cached using the old version even after they have been deleted and created again with the same name. This cache is only cleared once kubelet is restarted.

That means that any resource that is immutable burns the name forever. In order to still be able to update such resource we must generate a name randomly, so that new "versions" of that resource have a chance to be picked up.

This check will at least let us find instances where this would cause problems.