[ONOS-5731] Implement skeleton of VirtualNetworkPacketManager

Changes
1. Added VirtualNetworkPacketManager
2. Added VirtualNetworkPacketStore interface and impl class
3. Added VirtualPacketStore impl
4. Simple test cases are added

Todo
1. More test cases

Change-Id: I86f0484a9ee038dab8716703f0e5e41cbcf30cb1
diff --git a/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkLinkManagerTest.java b/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkLinkManagerTest.java
index 70f1c1b..a2062d9 100644
--- a/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkLinkManagerTest.java
+++ b/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/VirtualNetworkLinkManagerTest.java
@@ -72,6 +72,7 @@
         manager = new VirtualNetworkManager();
         manager.store = virtualNetworkManagerStore;
         manager.intentService = intentService;
+        manager.coreService = coreService;
         NetTestTools.injectEventDispatcher(manager, new TestEventDispatcher());
 
         testDirectory = new TestServiceDirectory();