ECK should not downgrade trial licensed clusters

[pebrc]

ECK currently enforces the license level of the operator on all managed Elasticsearch clusters. This can lead to a bad experience if a user started a trial in Kibana (which is possible through various "start trial" dialogues embedded in different places in the Kibana UI despite ECK disabling the license management UI, see APM example below)

ECK will in that case revert the cluster back to Basic because ECK itself is not running in trial mode.

I would suggest to change ECK's to not revert a trial licensed cluster back to a Basic license, because the trial cannot be started a second time.

We should still encourage users to use the documented ECK trial mechanism as it gives consistency across all managed clusters, but to avoid friction when trying out commercial stack features we should change behaviour as indicated.

[pebrc]

I also raised elastic/kibana#67606 because this button does nothing when the license UI is disabled.