[ONOS-4258] Initial implementation of supporting extension in REST

- Support Nicira extension

Change-Id: I62bf4417e43459727ce7d4b1ac929c6cf0b7826f
diff --git a/drivers/default/src/main/java/org/onosproject/driver/extensions/NiciraSetNshSi.java b/drivers/default/src/main/java/org/onosproject/driver/extensions/NiciraSetNshSi.java
index 3121803..ba1a55a 100644
--- a/drivers/default/src/main/java/org/onosproject/driver/extensions/NiciraSetNshSi.java
+++ b/drivers/default/src/main/java/org/onosproject/driver/extensions/NiciraSetNshSi.java
@@ -48,7 +48,7 @@
      *
      * @param nshSi nsh service index
      */
-    NiciraSetNshSi(NshServiceIndex nshSi) {
+    public NiciraSetNshSi(NshServiceIndex nshSi) {
         this.nshSi = nshSi;
     }