Only resolve artifacts in expanded environments for Java External transform

Only resolve artifacts in expanded environments for Java External transform.

We can't assume that any expansion service resolves any artifact information. For example, Java artifacts returned from Java expansion service cannot be resolved (+downloaded) with Python expansion service. Also, one Python expansion service may returns Python artifacts which are unknown to other Python expansion service. We need to skip pre-existing artifacts and only resolves artifacts in new environments from the expansion service at the moment.