Adding missing Keycloak "start" arg

General MR

Summary

The "start" argument was removed from the Keycloak package chart/values.yaml during the last renovate update. This MR adds the argument back in.

Relevant logs/screenshots

Issue reported by community member: https://bigbanguniver-ft39451.slack.com/archives/C051A2BPS0K/p1722513376742349

Linked Issue

issue #216

Upgrade Notices

N/A