Automatic merge from submit-queue (batch tested with PRs 47523, 47438, 47550, 47450, 47612)
kubeadm: Fix subtle versioning ordering issue with v1.8.0-alpha.0
**What this PR does / why we need it**:
`--kubernetes-version latest` is broken since it evals to `v1.8.0-alpha.0` which actually is `v1.7.0-beta.0`, so kubeadm enables features that don't exist
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #
**Special notes for your reviewer**:
**Release note**:
```release-note
NONE
```
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