Make fluentd-es output its warning logs and fluentd-gcp mount

cluster/saltbase/salt/fluentd-es/fluentd-es.yaml

@@ -11,7 +11,7 @@ spec:
       limits:
         cpu: 100m
     args:
-    - -qq
+    - -q
     volumeMounts:
     - name: varlog
       mountPath: /var/log

cluster/saltbase/salt/fluentd-gcp/fluentd-gcp.yaml

@@ -19,6 +19,7 @@ spec:
       mountPath: /varlog
     - name: containers
       mountPath: /var/lib/docker/containers
+      readOnly: true
   terminationGracePeriodSeconds: 30
   volumes:
   - name: varlog

docs/getting-started-guides/logging.md

@@ -182,6 +182,7 @@ spec:
       mountPath: /varlog
     - name: containers
       mountPath: /var/lib/docker/containers
+      readOnly: true
   terminationGracePeriodSeconds: 30
   volumes:
   - name: varlog