Export classesJars initialized in hiddenAPIExtractInformation

This exports classesJars constructed in hiddenAPIExtractInformation
through the hiddenAPIIntf interface for use by the
bootclasspath_fragment module type.

Bug: 179354495
Test: verified that the monolithic out/soong/hiddenapi/... files are
      unchanged by this change
Change-Id: Ic32f02a69229d9518772fe6b2a329501dd8cd849