Add extension.properties to eclipselink-extensibility-model.ear during running on application servers.
Add extension.properties to eclipselink-extensibility-model.ear during running on application servers.

Code reviewed by Yiping Zhao


Former-commit-id: 0423eb95bceaed37e6e0c9cd3cea66993503e070
bfg-repo-cleaner-demos/eclipselink.runtime-bfg-strip-big-blobs,bfg-repo-cleaner-demos/eclipselink.runtime-bfg-strip-big-blobs,bfg-repo-cleaner-demos/eclipselink.runtime-bfg-strip-big-blobs