Automatic merge from submit-queue (batch tested with PRs 60790, 66023, 67549). 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>. Removed istio related addon manifests, as the directory is deprecated. **What this PR does / why we need it**: the cluster/addon directory is deprecated, hence removing istio related addon manifests underneath. **Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*: Fixes # **Special notes for your reviewer**: **Release note**: ```release-note None ```