Describe the feature: Add automated tests for;

• Kibana starting while Elasticsearch is not running
• Kibana starting while Elasticsearch is running but not ready
• Kibana starting while Elasticsearch is running but writes are disabled
• Elasticsearch restarting while Kibana is running (this could span out to very many test cases where different actions are in progress when Elasticsearch restarts, but we should at least have 1 case where Kibana isn't doing anything and Elasticsearch restarts to verify Kibana re-connects)

Describe a specific use case for the feature:
We've had issues where Kibana can have a fatal error and fail to start if Elasticsearch isn't running or isn't ready. Kibana should always be robust, keep running, and keep trying to connect.