Fix for ONOS-4568 - Intents stuck in INSTALLING state

The default pipeline driver was not calling the success callback for
next objectives. This caused the intent installer to think there
were still flows in need of installation, and the intent never
completed.

Change-Id: Ib411c317b28475cfc1e966e31f859cebbeea3792
(cherry picked from commit ce7db1b6)

@@ -217,6 +217,7 @@ public class DefaultSingleTablePipeline extends AbstractHandlerBehaviour impleme
         pendingNext.put(nextObjective.id(), nextObjective);
         flowObjectiveStore.putNextGroup(nextObjective.id(),
                 new SingleGroup(new DefaultGroupKey(appKryo.serialize(nextObjective.id()))));
+        nextObjective.context().ifPresent(context -> context.onSuccess(nextObjective));
     }
 
     @Override