Refactored pseudowire code.

This refactoring is needed in order to be able to further
refactor the sr application in api / app / web, where api contains
the interfaces, used by other modules, app contains the implementations
and web contains rest related code.

Change-Id: I147442e5d1248941a6c3c4df2715b01e72c40b3f
diff --git a/src/main/java/org/onosproject/segmentrouting/pwaas/DefaultL2TunnelPolicy.java b/src/main/java/org/onosproject/segmentrouting/pwaas/DefaultL2TunnelPolicy.java
index ac52f3e..4738744 100644
--- a/src/main/java/org/onosproject/segmentrouting/pwaas/DefaultL2TunnelPolicy.java
+++ b/src/main/java/org/onosproject/segmentrouting/pwaas/DefaultL2TunnelPolicy.java
@@ -27,7 +27,7 @@
 /**
  * Implementation of the default l2 tunnel policy.
  */
-public class DefaultL2TunnelPolicy {
+public class DefaultL2TunnelPolicy implements L2TunnelPolicy {
 
     /**
      * Id of the tunnel associated to this policy.
@@ -97,65 +97,37 @@
         this.cP2OuterTag = policy.cP2OuterTag;
     }
 
-    /**
-     * Returns the first connect point of the policy.
-     *
-     * @return first connect point
-     */
+    @Override
     public ConnectPoint cP1() {
         return cP1;
     }
 
-    /**
-     * Returns the second connect point of the policy.
-     *
-     * @return second connect point
-     */
+    @Override
     public ConnectPoint cP2() {
         return cP2;
     }
 
-    /**
-     * Returns the cP1 inner vlan tag of the policy.
-     *
-     * @return cP1 inner vlan tag
-     */
+    @Override
     public VlanId cP1InnerTag() {
         return cP1InnerTag;
     }
 
-    /**
-     * Returns the cP1 outer vlan tag of the policy.
-     *
-     * @return cP1 outer vlan tag
-     */
+    @Override
     public VlanId cP1OuterTag() {
         return cP1OuterTag;
     }
 
-    /**
-     * Returns the cP2 inner vlan tag of the policy.
-     *
-     * @return cP2 inner vlan tag
-     */
+    @Override
     public VlanId cP2InnerTag() {
         return cP2InnerTag;
     }
 
-    /**
-     * Returns the cP2 outer vlan tag of the policy.
-     *
-     * @return cP2 outer vlan tag
-     */
+    @Override
     public VlanId cP2OuterTag() {
         return cP2OuterTag;
     }
 
-    /**
-     * Returns the tunnel ID of the policy.
-     *
-     * @return Tunnel ID
-     */
+    @Override
     public long tunnelId() {
         return this.tunnelId;
     }