CORD-349 Support VLAN cross-connect traffic

Change related to this topic:
- Support VLAN cross-connect traffic
    Utilize ports subjectClass to achieve. For non-xConnect port, set interface VLAN to -1
- Remove VLAN checking since we have multiple VLANs per port
- Hash the L2 interface group key generation to include VLAN as well
- Update the network-cfg.json sample

Other refactoring changes:
- Read next objective stores from srManager directly
- Use constant for flow priority
- CORD-267 Javadoc fix

Change-Id: I4ca8c2d9c8b3633a4a0101c5070d19343f7e5b90
diff --git a/src/main/java/org/onosproject/segmentrouting/Policy.java b/src/main/java/org/onosproject/segmentrouting/Policy.java
index 2e41795..6133254 100644
--- a/src/main/java/org/onosproject/segmentrouting/Policy.java
+++ b/src/main/java/org/onosproject/segmentrouting/Policy.java
@@ -24,16 +24,24 @@
      * Enums for policy type.
      */
     enum Type {
-        // Tunnel flow policy type
+        /**
+         * Tunnel flow policy type.
+         */
         TUNNEL_FLOW,
 
-        // Load balancing policy type
+        /**
+         * Load balancing policy type.
+         */
         LOADBALANCE,
 
-        // policy to avoid specific routers or links
+        /**
+         * policy to avoid specific routers or links.
+         */
         AVOID,
 
-        // Access Control policy type
+        /**
+         * Access Control policy type.
+         */
         DENY
     }