pull-kubernetes-e2e-gce-ubuntu-containerd has been the main CI job in presubmit that runs all the e2e tests for a while now. Historic note is that it replaced a job named pull-kubernetes-e2e-gce so we had added the qualifer that this was a ubuntu OS running containerd when we added this job. At this point since this is the default job, let's give it the shorter name.

Notes from @BenTheElder on slack:

• Not sure if prow status reconciler can handle this. We may end up with wrong status(es) everywhere
• In the past we did renames and prow handling them by updating the statuses on rename
• We probably need to do it before test freeze, or early next cycle
• Status Reconciler is here : https://github.com/kubernetes/test-infra/blob/ca06d20ff4c490bc07aefe05409e0741e76bd5e7/prow/cmd/status-reconciler/README.md
• We also have the manual bulk migratestatus tool that @spiffxp or another github admin can run anyhow if we have to