e2e: node: expose the running flag

Each e2e test knows it wants to restart a running kubelet or a
non-running kubelet. The vast majority of times, we want to
restart a running kubelet (e.g. to change config or to check
some properties hold across kubelet crashes/restarts), but sometimes
we stop the kubelet, do some actions and only then restart.

To accomodate both use cases, we just expose the `running` boolean
flag to the e2e tests.

Having the `restartKubelet` explicitly restarting a running kubelet
helps us to trobuleshoot e2e failures on which the kubelet
was supposed to be running, while it was not; attempting a restart
in such cases only murkied the waters further, making the
troubleshooting and the eventual fix harder.

In the happy path, no expected change in behaviour.

Signed-off-by: Francesco Romani <fromani@redhat.com>

test/e2e_node/memory_manager_test.go

@@ -348,7 +348,7 @@ var _ = SIGDescribe("Memory Manager [Serial] [Feature:MemoryManager]", func() {
 				return kubeletHealthCheck(kubeletHealthCheckURL)
 			}, time.Minute, time.Second).Should(gomega.BeFalse())
 
-			restartKubelet()
+			restartKubelet(false)
 
 			// wait until the kubelet health check will pass
 			gomega.Eventually(func() bool {