HTTP Caching

I am using http storage plugin and I want to activate the caching. In the documentation it says that this requires adding cacheResults. So I added this to my config. When I test using an older version(1.20.1), I can see the query result files under the tmp/http-cache directory, but when I test using a newer version(1.21.1), there are no query result files in that directory, it only contains the journal. This PR https://github.com/apache/drill/pull/2669 may have caused the issue.

Also, is it possible to implement maximum cache size?