Fix gatweay type duplicate issue in admin portal

Author: msm1992

components/apimgt/org.wso2.carbon.apimgt.rest.api.admin.v1/src/main/java/org/wso2/carbon/apimgt/rest/api/admin/v1/utils/mappings/SettingsMappingUtil.java

@@ -152,9 +152,10 @@ private static List<SettingsFederatedGatewayConfigurationDTO> getSettingsFederat
             SettingsFederatedGatewayConfigurationDTO gateway = new SettingsFederatedGatewayConfigurationDTO();
             gateway.setType(type);
             gateway.setDisplayName(type);
-            list.add(gateway);
+            if (list.stream().noneMatch(obj -> obj.getType().equals(type))) {
+                list.add(gateway);
+            }
         }
-
         return list;
     }