Remove default flow rules for ROADMs. Fix LinkResource NPE. Single instance provisions optical path.

Change-Id: Iacbd41403ecd0c0df240d09026253c4b761a1d6a
diff --git a/core/net/src/main/java/org/onosproject/net/packet/impl/PacketManager.java b/core/net/src/main/java/org/onosproject/net/packet/impl/PacketManager.java
index 18989bb..8908601 100644
--- a/core/net/src/main/java/org/onosproject/net/packet/impl/PacketManager.java
+++ b/core/net/src/main/java/org/onosproject/net/packet/impl/PacketManager.java
@@ -220,6 +220,11 @@
      * @param request the packet request
      */
     private void pushRule(Device device, PacketRequest request) {
+        // Everything is pre-provisioned on ROADMs
+        if (device.type().equals(Device.Type.ROADM)) {
+            return;
+        }
+
         TrafficTreatment treatment = DefaultTrafficTreatment.builder()
                                                             .punt()
                                                             .build();