Set imagePullPolicy to IfNotPresent in multisite example

Using `imagePullPolicy: IfNotPresent` reduces registry traffic,
speeds up pod restarts.

This affects only the example manifest and does not change controller
behavior for existing clusters unless they adopt this setting.

This is also consistent with the rest of examples.

Change-Id: I42b21d9c621ca406885989d7e4ba509c1ab53a34
diff --git a/Documentation/examples/gerritcluster-3-nodes-pr-kafka-multisite.yaml b/Documentation/examples/gerritcluster-3-nodes-pr-kafka-multisite.yaml
index 4d9a31e..f6daccf 100644
--- a/Documentation/examples/gerritcluster-3-nodes-pr-kafka-multisite.yaml
+++ b/Documentation/examples/gerritcluster-3-nodes-pr-kafka-multisite.yaml
@@ -22,6 +22,8 @@
   name: gerrit
   namespace: gerrit
 spec:
+  containerImages:
+    imagePullPolicy: IfNotPresent
   eventsBroker:
     brokerType: KAFKA
     kafkaConfig: