When a broker starts up it can handle metadata requests before it has
received UPDATE_METADATA requests from the controller.
This manifests in the admin client via:
- listTopics returning an empty list
- describeTopics and describeConfigs of topics erroneously returning TopicOrPartitionNotFoundException
I assume this also affects the producer and consumer, though since `UnknownTopicOrPartitionException` is retriable those clients recover.
Testing locally suggests that the window for this happening is typically <1s.
There doesn't seem to be any way for the caller of the Admin client to detect this situation.