Major Description
See the discussion in SOLR-5865, namely:
The main reason most of the cloud tests have gone with specifying which config files to put in zk was that uploading the entire directory of test configs was damn slow and then repeated for all cloud tests.
A better solution at some point would be a new test config folder just for solrcloud. We already have a lot of configs, but we could probably merge some things into this - like the common solrconfig and schema that almost all cloud tests use anyway. If we kept it to one set, I think it would be an improvement for cloud tests.