Add readOnlyRootFilesystem to HAProxy and CoreDNS.

- Added security context readOnlyRootFilesystem as true.

Change-Id: I84ea5a17f84bebac795e7ed72a7dff530ef081bb

charts/haproxy/templates/daemonset.yaml

@@ -67,6 +67,8 @@ spec:
               mountPath: /tmp/etc
             - name: host
               mountPath: /host
+      securityContext:
+        readOnlyRootFilesystem: true
       volumes:
         - name: haproxy-bin
           configMap:

charts/haproxy/templates/etc/_haproxy.yaml.tpl

@@ -91,3 +91,5 @@ spec:
     - name: etc
       hostPath:
         path: {{ .Values.conf.haproxy.host_config_dir }}
+  securityContext:
+    readOnlyRootFilesystem: true