Refactor: move RulePopulatorUtil into util package, w/ minor fixes

Change-Id: I359040c0e81bfcc0acc32a2299782f442f56a1d3
diff --git a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingFloatingIpHandler.java b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingFloatingIpHandler.java
index bfe0257..1255838 100644
--- a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingFloatingIpHandler.java
+++ b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingFloatingIpHandler.java
@@ -71,7 +71,7 @@
 import static org.onosproject.openstacknetworking.api.Constants.PRIORITY_FLOATING_EXTERNAL;
 import static org.onosproject.openstacknetworking.api.Constants.PRIORITY_FLOATING_INTERNAL;
 import static org.onosproject.openstacknetworking.api.Constants.ROUTING_TABLE;
-import static org.onosproject.openstacknetworking.impl.RulePopulatorUtil.buildExtension;
+import static org.onosproject.openstacknetworking.util.RulePopulatorUtil.buildExtension;
 import static org.onosproject.openstacknode.api.OpenstackNode.NodeType.GATEWAY;
 
 /**