BUG-731: add final modifiers

These members are constants, mark them as such.

Change-Id: Ied83e05dba3dfd3cebae1afd821253796c236093
Signed-off-by: Robert Varga <rovarga@cisco.com>
(cherry picked from commit c9bb8ccc7cd14e58ccaaec3de788b270efb0c5bd)
Signed-off-by: Robert Varga <rovarga@cisco.com>