Replace dismissed zookeeper Bitnami Helm chart

Bitnami’s ZooKeeper Helm chart and related images became private in
August 2025 [1], breaking the documented installation path. Update the
operator documentation to use the publicly available
`rhcharts/zookeeper` chart for local testing.

This change is intended only for non-production environments. The chart
defaults to the Confluent ZooKeeper image (e.g.,
`confluentinc/cp-zookeeper:7.3.0`). See the chart’s documentation for
additional configuration [2].

[1]: https://github.com/bitnami/charts/tree/main/bitnami/zookeeper#%EF%B8%8F-important-notice-upcoming-changes-to-the-bitnami-catalog
[2]: https://ricardo-aires.github.io/helm-charts/

Change-Id: Ic84d4ed7b1b7a66649403bb4aed59eb4e09da942

Documentation/examples/5-gerritcluster-refdb.yaml

diff --git a/Documentation/examples/5-gerritcluster-refdb.yaml b/Documentation/examples/5-gerritcluster-refdb.yaml
index 5f073fa..4bd3175 100644
--- a/Documentation/examples/5-gerritcluster-refdb.yaml
+++ b/Documentation/examples/5-gerritcluster-refdb.yaml
@@ -31,7 +31,7 @@
   refdb:
     database: ZOOKEEPER
     zookeeper:
-      connectString: zookeeper.zookeeper.svc.cluster.local:2181
+      connectString: zookeeper-headless.zookeeper.svc.cluster.local:2181
 
   # All Gerrit instances in the GerritCluster serve the same repositories and
   # thus have to use the same serverId, which has to be set centrally here.

Documentation/examples/6-gerritcluster-ha-primary.yaml

diff --git a/Documentation/examples/6-gerritcluster-ha-primary.yaml b/Documentation/examples/6-gerritcluster-ha-primary.yaml
index 9bdfb3d..2e74d28 100644
--- a/Documentation/examples/6-gerritcluster-ha-primary.yaml
+++ b/Documentation/examples/6-gerritcluster-ha-primary.yaml
@@ -31,7 +31,7 @@
   refdb:
     database: ZOOKEEPER
     zookeeper:
-      connectString: zookeeper.zookeeper.svc.cluster.local:2181
+      connectString: zookeeper-headless.zookeeper.svc.cluster.local:2181
 
   # All Gerrit instances in the GerritCluster serve the same repositories and
   # thus have to use the same serverId, which has to be set centrally here.

Documentation/operator.md

diff --git a/Documentation/operator.md b/Documentation/operator.md
index 93d9206..f7dee68 100644
--- a/Documentation/operator.md
+++ b/Documentation/operator.md
@@ -632,7 +632,16 @@
 ```sh
 kubectl create ns zookeeper
 kubectl label namespace zookeeper istio-injection=enabled
-helm upgrade --install zookeeper oci://registry-1.docker.io/bitnamicharts/zookeeper -n zookeeper
+
+helm repo add rhcharts https://ricardo-aires.github.io/helm-charts/
+helm repo update
+helm upgrade --install zookeeper rhcharts/zookeeper \
+  --version 0.2.0 \
+  --namespace zookeeper \
+  --set image.repository=confluentinc/cp-zookeeper \
+  --set image.tag=7.3.0 \
+  --set replicaCount=1 \
+  --set persistence.enabled=false
 ```
 
 Now, the GerritCluster can be configured to use the Global RefDB. Since the