Automatic merge from submit-queue (batch tested with PRs 51733, 51838) Decouple kube-proxy upgrade/downgrade tests from upgradeTests **What this PR does / why we need it**: Fixes the failing kube-proxy migration CI jobs: - https://k8s-testgrid.appspot.com/sig-network#gci-gce-latest-upgrade-kube-proxy-ds - https://k8s-testgrid.appspot.com/sig-network#gci-gce-latest-downgrade-kube-proxy-ds **Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #51729 **Special notes for your reviewer**: /assign @krousey @nicksardo Could you please take a look post code-freeze (I believe it is fixing things)? Thanks! **Release note**: ```release-note NONE ```