Add LevelDB as build dependency for DB8

Add LevelDB to the build.  GF-4872

Open-webOS-DCO-1.0-Signed-off-by: Roger Stringer <roger.stringer@lge.com>

Change-Id: Ie86df4a84bb33e77d3de9e20c58436ccb63cb23a
Reviewed-on: https://g2g.palm.com/2070
Reviewed-by: Roger Stringer <roger.stringer@lge.com>
Tested-by: Roger Stringer <roger.stringer@lge.com>
Reviewed-by: Iyad Qumei <iyad.qumei@lge.com>
Reviewed-by: Build Verification
Reviewed-by: Susan Montooth <susan.montooth@lge.com>