Java SDK - Triage initial setup

[booniepepper]

Something about generating the Java SDK requires building twice.

See: #160 (comment)

Here's a gist with a failure: https://gist.github.com/booniepepper/0e197ea5b3c2a297338115f7eee4bb27

Subsequent builds work just fine

[booniepepper]

Note: Java is the first SDK generated in this project where the OpenAPI generator template name of "Java" was not all lowercase characters.

No clue if this is related or not, but it's the first thing that comes to mind on differences between this client and others.