don't depend on PhysicalNetworkResponse for PhysicalNetworkTrafficType.isolationMethods

Author: madhukar93

api/src/main/java/org/apache/cloudstack/api/response/PhysicalNetworkResponse.java

@@ -139,10 +139,6 @@ public void setIsolationMethods(List<String> isolationMethods) {
         this.isolationMethods = buf.delete(buf.length() - 1, buf.length()).toString();
     }
 
-    public String getIsolationMethods() {
-        return isolationMethods;
-    }
-
     public void setName(String name) {
         this.name = name;
     }

server/src/main/java/com/cloud/api/ApiResponseHelper.java

@@ -3082,10 +3082,9 @@ public TrafficTypeResponse createTrafficTypeResponse(PhysicalNetworkTrafficType
         PhysicalNetwork pnet = ApiDBUtils.findPhysicalNetworkById(result.getPhysicalNetworkId());
         if (pnet != null) {
             response.setPhysicalNetworkId(pnet.getUuid());
-            // using PhysicalNetworkResponse only to convert isolation methods to string
-            PhysicalNetworkResponse pnetResponse = new PhysicalNetworkResponse();
-            pnetResponse.setIsolationMethods(pnet.getIsolationMethods());
-            response.setIsolationMethods(pnetResponse.getIsolationMethods());
+            if (!pnet.getIsolationMethods().isEmpty()) {
+                response.setIsolationMethods(String.join(",", pnet.getIsolationMethods()));
+            }
         }
         if (result.getTrafficType() != null) {
             response.setTrafficType(result.getTrafficType().toString());