Merge pull request kubernetes#121943 from dims/replace-E-with-setenv-for-systemd-run-parameter

Replace -E with --setenv for systemd-run parameter

Author: k8s-ci-robot

test/e2e_node/services/kubelet.go

@@ -250,7 +250,7 @@ func (e *E2EServices) startKubelet(featureGates map[string]bool) (*server, error
 		cmdArgs = append(cmdArgs,
 			systemdRun,
 			// Set the environment variable to enable kubelet config drop-in directory.
-			"-E", "KUBELET_CONFIG_DROPIN_DIR_ALPHA=yes",
+			"--setenv", "KUBELET_CONFIG_DROPIN_DIR_ALPHA=yes",
 			"-p", "Delegate=true",
 			"-p", logLocation+framework.TestContext.ReportDir+"/kubelet.log",
 			"--unit="+unitName,