Remove Java Buildpack Dependencies from Blobstore

This change removes the Java Buildpack dependencies from the
blobstore.  The new "offline" design used by the buildpack means that
these dependencies are no longer needed.

The removal of these dependencies shrinks the blobstore by ~583 MB.

[#70160258]
Merge pull request #374 from nebhale/70160258-remove-buildpack-cached-dependencies

Remove Java Buildpack Dependencies from Blobstore