[ONOS-2736] Fix bug of getting json from subnet.

Change-Id: I386f622fba74f0303a5ed9e6820ebc68a817021d
diff --git a/apps/vtnrsc/src/main/java/org/onosproject/vtnrsc/web/SubnetCodec.java b/apps/vtnrsc/src/main/java/org/onosproject/vtnrsc/web/SubnetCodec.java
index 8f0fd2e..afd561f 100644
--- a/apps/vtnrsc/src/main/java/org/onosproject/vtnrsc/web/SubnetCodec.java
+++ b/apps/vtnrsc/src/main/java/org/onosproject/vtnrsc/web/SubnetCodec.java
@@ -32,15 +32,19 @@
         checkNotNull(subnet, "Subnet cannot be null");

         ObjectNode result = context.mapper().createObjectNode()

                 .put("id", subnet.id().toString())

-                .put("gate_ip", subnet.gatewayIp().toString())

+                .put("gateway_ip", subnet.gatewayIp().toString())

                 .put("network_id", subnet.networkId().toString())

                 .put("name", subnet.subnetName().toString())

                 .put("ip_version", subnet.ipVersion().toString())

                 .put("cidr", subnet.cidr().toString())

                 .put("shared", subnet.shared())

                 .put("enabled_dchp", subnet.dhcpEnabled())

-                .put("tenant_id", subnet.tenantId().toString());

-        result.set("alloction_pools", new AllocationPoolsCodec().encode(subnet

+                .put("tenant_id", subnet.tenantId().toString())

+                .put("ipv6_address_mode", subnet.ipV6AddressMode() == null ? null

+                          : subnet.ipV6AddressMode().toString())

+                .put("ipv6_ra_mode", subnet.ipV6RaMode() == null ? null

+                          : subnet.ipV6RaMode().toString());

+        result.set("allocation_pools", new AllocationPoolsCodec().encode(subnet

                 .allocationPools(), context));

         result.set("host_routes",

                    new HostRoutesCodec().encode(subnet.hostRoutes(), context));