Fix Helm canary upgrade doc tests

Doc tests are failing, probably a change in Istio where the change was not made in docs. Ran out of time to troubleshoot and we need to finish branching. Canary upgrades are working, just some output seems to have changed.

Failed CI run: https://prow.istio.io/view/gs/istio-prow/pr-logs/pull/istio_istio.io/16729/doc.test.profile-none_istio.io/1950909270685913088