Automatic merge from submit-queue (batch tested with PRs 57322, 57723, 58706, 59004, 58857). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
Adding downgrade test for ingress-gce
**What this PR does / why we need it**:
This PR improves the existing downgrade e2e test for ingress-gce. Specifically, we add a test which downgrades ingress from an image built from HEAD to the latest release image.
```release-note
None
```