add readOnlyRootFilesystem: true to the Operator

Author: Peng Zhou

charts/marklogic-operator-kubernetes/values.yaml

@@ -10,6 +10,7 @@ controllerManager:
       capabilities:
         drop:
         - ALL
+      readOnlyRootFilesystem: true
       runAsNonRoot: true
     image:
       repository: gcr.io/kubebuilder/kube-rbac-proxy
@@ -31,6 +32,7 @@ controllerManager:
       capabilities:
         drop:
         - ALL
+      readOnlyRootFilesystem: true
       runAsNonRoot: true
     image:
       repository: progressofficial/marklogic-operator-kubernetes