Automatic merge from submit-queue (batch tested with PRs 40665, 41094, 41351, 41721, 41843)
kubeadm: Add a --ca-cert-path flag to kubeadm join
**What this PR does / why we need it**:
This PR makes it possible to customize where the CA file is written
**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
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@pires @mikedanese @dmmcquay @jbeda @errordeveloper