Ephemeral storage should extend to ZK instance

[mogul]

When you specify the ephemeral storage type for a solrcloud, that should also extend to the Zookeeper instance that the solr-operator manages (specified like this).

(We noted this when the ZK pod did not start on AWS Fargate because it was trying to use a persistent volume claim, so the SolrCloud pod did not start either despite using emptyDir.)

[HoustonPutman]

Agreed. This is a good feature that should be included in v0.4.0.

We should expose all options for the Zookeeper storage, but default to ephemeral/persistent depending on what the SolrCloud uses.

[jward-bw]

We should expose all options for the Zookeeper storage, but default to ephemeral/persistent depending on what the SolrCloud uses.

This is important, in our use-case we probably will have solr data on ephemeral but ZK on persistent.