Automatic merge from submit-queue (batch tested with PRs 36990, 37494, 38152, 37561, 38136)

Pass proxy environment variables to static pods

**What this PR does / why we need it**:

To access outside world or cloud provider APIs it might be
required to use proxy. kubeadm will be passing proxy variables to static pods during init stage.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes kubernetes/kubernetes#36573, kubernetes/kubeadm#5

**Special notes for your reviewer**:

**Release note**:
```release-note
- kubeadm will pass proxy environment variables to static pods.
```