Migrate ZooKeeper Docker image and Helm chart from Bitnami

[yashmayya]

• See Override ZooKeeper Docker image repo for Bitnami Helm chart #16984.
• Bitnami has pulled support for their free tier images (Upcoming changes to the Bitnami catalog (effective August 28th, 2025) bitnami/charts#35164). So there will be no new Docker images published, and the existing ones have been moved from the bitnami repo to bitnamilegacy (see https://hub.docker.com/r/bitnami/zookeeper).
• We need to move away from using the Bitnami Helm Chart and Docker image for ZooKeeper given that they will no longer be maintained and upgraded. This is the official ZooKeeper Docker image, but there don't appear to be any viable Helm chart alternatives. We might need to create our own.