Allows our readiness probe with zookeeper >=3.5.3

Without this zookeeper would reply: ruok is not executed because it is not in the whitelist

Fixes #298, according to tests with variants/dev-small and regular apply -k on k3s

Author: solsson

zookeeper/10zookeeper-config.yml

@@ -22,6 +22,7 @@ data:
     sed -i "s/server\.$ZOOKEEPER_SERVER_ID\=[a-z0-9.-]*/server.$ZOOKEEPER_SERVER_ID=0.0.0.0/" /etc/kafka/zookeeper.properties
 
   zookeeper.properties: |
+    4lw.commands.whitelist=ruok
     tickTime=2000
     dataDir=/var/lib/zookeeper/data
     dataLogDir=/var/lib/zookeeper/log