Merge pull request #62135 from jiayingz/kubelet-restart-fix

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Fixes restartKubelet in test/e2e_node failure.

Looks like there is some recent change on how we start kubelet service
in test_e2e_node. Fixes restartKubelet() to get right kubelet service
name to cope with the change.



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

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes kubelet-serial-gce-e2e test failure:
https://k8s-testgrid.appspot.com/wg-resource-management#kubelet-serial-gce-e2e
Thanks a lot to @mindprince for noticing this!

**Special notes for your reviewer**:

**Release note**:

```release-note

```

test/e2e_node/util.go

@@ -399,7 +399,7 @@ func getCRIClient() (internalapi.RuntimeService, internalapi.ImageManagerService
 func restartKubelet() {
 	stdout, err := exec.Command("sudo", "systemctl", "list-units", "kubelet*", "--state=running").CombinedOutput()
 	framework.ExpectNoError(err)
-	regex := regexp.MustCompile("(kubelet-[0-9]+)")
+	regex := regexp.MustCompile("(kubelet-\\w+)")
 	matches := regex.FindStringSubmatch(string(stdout))
 	Expect(len(matches)).NotTo(BeZero())
 	kube := matches[0]