Automatic merge from submit-queue (batch tested with PRs 54107, 54184, 54377, 54094, 54111). 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>. add e2e tests for NEG This PR includes tests: - ingress conformance test - scaling up and down backends - switching backend between IG and NEG - rolling update backend should not cause service disruption ```release-note NONE ```