JERSEY-2551: Injections#generator field is hard coded to ServiceLocatorGeneratorImpl

 - fix + integration test

Change-Id: I61c859d258b123bed718a987671a72dd2f0f6aa3
Signed-off-by: Michal Gajdos <michal.gajdos@oracle.com>
Merge "JERSEY-2551: Injections#generator field is hard coded to ServiceLocatorGeneratorImpl"