Build docker image if not available

## Summary

A recent bug in mule is that if an image isn't available, it will not attempt to build it. This can be a blocker to executing tasks. In particular, I found this to be a blocker when trying to run the package-sign task.

## Scope/Requirements

Update mule to restore the build functionality. As a bonus, add the option to upload it to a repository so others can use it (and we can eventually pipeline automate it).

## Urgency/Relative Priority

We can work around this in many cases, but not all cases. When we rotate duties, if someone has not built this image, then it may result in an inability to execute mule tasks.