fixing connector validation (#3461)

Signed-off-by: Dhrubo Saha <dhrubo@amazon.com>
(cherry picked from commit a6eaf08)

Author: dhrubo-os

plugin/src/main/java/org/opensearch/ml/action/register/TransportRegisterModelAction.java

@@ -270,7 +270,19 @@ private void doRegister(MLRegisterModelInput registerModelInput, ActionListener<
                         mlFeatureEnabledSetting,
                         ActionListener.wrap(r -> {
                             if (Boolean.TRUE.equals(r)) {
-                                createModelGroup(registerModelInput, listener);
+                                if (registerModelInput.getModelInterface() == null) {
+                                    mlModelManager
+                                        .getConnector(
+                                            registerModelInput.getConnectorId(),
+                                            registerModelInput.getTenantId(),
+                                            ActionListener.wrap(connector -> {
+                                                updateRegisterModelInputModelInterfaceFieldsByConnector(registerModelInput, connector);
+                                                createModelGroup(registerModelInput, listener);
+                                            }, listener::onFailure)
+                                        );
+                                } else {
+                                    createModelGroup(registerModelInput, listener);
+                                }
                             } else {
                                 listener
                                     .onFailure(

plugin/src/main/java/org/opensearch/ml/model/MLModelManager.java

@@ -2066,7 +2066,7 @@ public void getController(String modelId, ActionListener<MLController> listener)
      * @param tenantId tenant id
      * @param listener    action listener
      */
-    private void getConnector(String connectorId, String tenantId, ActionListener<Connector> listener) {
+    public void getConnector(String connectorId, String tenantId, ActionListener<Connector> listener) {
         GetDataObjectRequest getDataObjectRequest = GetDataObjectRequest
             .builder()
             .index(ML_CONNECTOR_INDEX)