[Enhancement]: Tag aio image with static tag

[jbpratt]

What would you like to be added:

Currently the all-in-one image is published with the build date like so: quay.io/microshift/microshift:4.7.0-0.microshift-2021-08-31-224727-aio. I would like a static tag on an image (latest, aio, latest-aio or anything else that seems fit). Publishing an image such as quay.io/microshift/microshift-aio:latest may help differentiate it from the main image if there is any confusion between them.

Why is this needed:

Podman auto-update's feature to work as implemented in #292.

<snip>
An image is considered updated if the digest in the local storage is different
than the one of the remote image. If an image must be updated, Podman pulls it
down and restarts the systemd unit executing the container.

The registry policy requires a fully-qualified image reference (e.g.,
quay.io/podman/stable:latest) to be used to create the container. This
enforcement is necessary to know which image to actually check and pull.
</snip>

[rootfs]

/assign @copejon

[sallyom]

Once this issue is addressed, we need to update this: https://github.com/redhat-et/microshift/blob/42a27223f94db4686dc2f0d2bdc697ae2af7efaa/hack/all-in-one/microshift-aio-run#L20

[copejon]

I've created a new repo to house the aoi images (https://quay.io/repository/microshift/microshift-aoi). We'll need to adjust PR #319 such that AIO images are tagged accordingly.

[jbpratt]

adding this since @copejon meant aio 😸 https://quay.io/repository/microshift/microshift-aio

[jbpratt]

Marking this as closed since we have a static tag for the AIO image