use different location for local maven repo based on OSO versus OSD

[jstrachan]

When using OSO we're gonna be restricting builds to 1 concurrent build per user. In which case its safe to have a write once PV for the local mvn repo for doing CD releases or for snapshot builds

However when using OSD we probably want to use the job workspace as the local maven repository so that we can have parallel builds running and avoid overwriting each other or causing inconsistencies in the builds.

So we maybe need a configuration to know if we can use a single read/write once; use a read/write many or use workspace based persistence for builds. Some folks may want to disable persistence too maybe?

Maybe we need a ConfigMap we load to configure these kinds of things?