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kubeadm: add mandatory phase "annotate-cri"

**What this PR does / why we need it**:
In v1.12, after the changing how kubeadm-config upload/fetch, AnnotateCRISocket is now a necessary step for getting a cluster that can be upgraded using phases. This PR adds a new subcommand for letting users to invoke AnnotateCRISocket as a phase

**Which issue(s) this PR fixes**:
Fixes # https://github.com/kubernetes/kubeadm/issues/925

**Special notes for your reviewer**:
When testing this PR, I found that one of the tests on component config defaulting was broken (didn't have time to investigate why yet). This PR fixes this test as well  

**Release note**:
```release-note
kubeadm: added phase command "alpha phase kubelet config annotate-cri"
```
@kubernetes/sig-cluster-lifecycle-pr-reviews
/sig cluster-lifecycle
/area kubeadm
/assign @timothysc @neolit123 
/kind bug