Fix for ONOS-5175. GroupId refactoring.

Change-Id: I951392bdc69fe1ef694d321164b0b49032617d6b
diff --git a/core/common/src/test/java/org/onosproject/codec/impl/GroupJsonMatcher.java b/core/common/src/test/java/org/onosproject/codec/impl/GroupJsonMatcher.java
index 445d0c2..f1c9068 100644
--- a/core/common/src/test/java/org/onosproject/codec/impl/GroupJsonMatcher.java
+++ b/core/common/src/test/java/org/onosproject/codec/impl/GroupJsonMatcher.java
@@ -38,7 +38,7 @@
     public boolean matchesSafely(JsonNode jsonGroup, Description description) {
         // check id
         String jsonGroupId = jsonGroup.get("id").asText();
-        String groupId = group.id().toString();
+        String groupId = group.id().id().toString();
         if (!jsonGroupId.equals(groupId)) {
             description.appendText("group id was " + jsonGroupId);
             return false;