Automatic merge from submit-queue De-flaking E2E: PersistentVolumes[Disruptive] - restart kubelet via service manager CLI Current process for restarting the kubelet accesses `/etc/init.d/kubelet`, which is not a common path across OSes. This PR changes the behavior of `kubeletCommand()` to instead attempt restarting the kubelet service through the system manager CLI. It first attempts a systemd call, then falls back to sysVinit. If neither calls work, the test exits. This PR _does not_ remove `[Flaky]`. Right now, the test fails consistently in the gci-gce-flaky suite. After merge, I'll monitor the test grid for ~week. If no flakes appear, I'll submit a pr to pull the Flaky tag off. Additional Changes - Improved error messages - Cleanup on failure in `initTestCase` Fixes #44933 **Release note**: ```release-note NONE ```