Add blank line between java and javax imports

[philwebb]

Currently it's impossible to configure Eclipse to organize imports in a way that makes checkstyle happy. There's no way to not add the gap between java and javax.

Rather than fighting the IDE, we could consider changing the import rules.

[philwebb]

Some discussion about this is in our internal Slack room.

[sbrannen]

Thanks for raising the issue, @philwebb.

I'm fully in favor of making this change to our formatting since it will significantly simplify matters for developers that use Eclipse as an IDE, and it would also align with many other Spring portfolio projects.

[sbrannen]

Team Decision: proceed with the proposal to add a blank line between java and javax imports.