[helm] correct the internal listening address configuration for coordinator-server

[bbb4aaa]

Purpose

The purpose of this change is to fix a connectivity issue between clients and the coordinator-server when Fluss is deployed via Helm. Previously, the INTERNAL listener was bound to 0.0.0.0, which caused the server to register itself with an ambiguous address. This prevented clients from correctly resolving the coordinator-server location during the CREATE CATALOG process via bootstrap.servers.

Brief change log

• Modified helm/templates/sts-coordinator.yaml to change the INTERNAL listener bind address from 0.0.0.0 to ${POD_IP}.
• This ensures that the coordinator-server registers its specific Pod IP for internal cluster communication, allowing metadata requests and bootstrap connections (e.g., coordinator-server-hs.fluss:9123) to succeed:
  CREATE CATALOG fluss_catalog WITH ( 'type' = 'fluss', 'bootstrap.servers' = 'coordinator-server-hs.fluss:9123' );

Tests

• Verified by deploying Fluss in a Kubernetes cluster using the updated Helm chart.
• Confirmed that Flink SQL CREATE CATALOG commands now succeed without errors.
• Manual verification of $FLUSS_HOME/conf/server.yaml inside the coordinator pod to ensure the bind.listeners property is correctly rendered with the Pod's IP.

API and Format

• This change does not affect public APIs or storage formats. It only modifies the network binding configuration in the Kubernetes deployment template.

Documentation

• No changes to formal documentation are required as this is a bug fix for the deployment configuration.