- set to 5 seconds by default - address compatibility with Kubernetes 1.20+. This impacts "bin/pulsar-zookeeper-ruok.sh" exec probe used in ZK. "Before Kubernetes 1.20, the field timeoutSeconds was not respected for exec probes: probes continued running indefinitely, even past their configured deadline, until a result was returned." https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-startup-probes/#configure-probes