Automatic merge from submit-queue (batch tested with PRs 36263, 36755, 37357, 37222, 37524)
kubeadm: Skip etcd related preflight checks and reset actions for external etcd
**What this PR does / why we need it**:
Skip etcd related preflight checks and reset actions for external etcd
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes # https://github.com/kubernetes/kubeadm/issues/69#issuecomment-262988388
**Special notes for your reviewer**:
**Release note**:
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```release-note
kubeadm: Skip etcd related preflight checks and reset actions for external etcd
```