Update gateway type validation

Author: msm1992

components/apimgt/org.wso2.carbon.apimgt.rest.api.admin.v1/src/main/java/org/wso2/carbon/apimgt/rest/api/admin/v1/impl/EnvironmentsApiServiceImpl.java

@@ -111,10 +111,12 @@ public Response environmentsPost(EnvironmentDTO body, MessageContext messageCont
             //String tenantDomain = RestApiCommonUtil.getLoggedInUserTenantDomain();
             String organization = RestApiUtil.getValidatedOrganization(messageContext);
             String gatewayType = body.getGatewayType();
-            //todo: temporarily disabling the gateway type validation
-//            if (!(APIConstants.API_GATEWAY_TYPE_REGULAR.equals(gatewayType) || APIConstants.API_GATEWAY_TYPE_APK.equals(gatewayType))) {
-//                throw new APIManagementException("Invalid gateway type: " + gatewayType);
-//            }
+
+            List<String> gatewayTypes = APIUtil.getGatewayTypes();
+            if (!gatewayTypes.contains(gatewayType)) {
+                throw new APIManagementException("Invalid gateway type: " + gatewayType);
+            }
+            
             if (APIConstants.API_GATEWAY_TYPE_APK.equals(gatewayType) && hasUnsupportedVhostConfiguration(body.getVhosts())) {
                 throw new APIManagementException("Unsupported Vhost Configuration for gateway type: " + gatewayType);
             }