Only give a DOI to public ARCs

[SabrinaZander]

Yesterday we published an ARC that was set to private.
I thought it would automatically be set to public after the publishing process.
But after the publishing process, the ARC was still private and we have to manually set it to public.
It would be good if only public ARCs could get a DOI or the ARC would automatically be set to public after the publishing process.
Otherwise you have a DOI but nobody can access the ARC, which is not how it should be.