Determine whether to ignore keys for "unsupported/unwanted regions"

[mattleibow]

Right now, I think the function accepts any region provided, but still only batches the supported ones. Potentially this will be a waste, since after 14 day they are deleted. But, we should probably filter them out.

[Redth]

We should probably just accept the request and return an ok result but not store the keys. I'm assuming if the app is generating keys for a region, since the health authority owns the server, they'll update the server config as well.