hanlde the throttling error in the response header

Signed-off-by: Xun Zhang <xunzh@amazon.com>

Author: Zhangxunmt

ml-algorithms/src/main/java/org/opensearch/ml/engine/algorithms/remote/MLSdkAsyncHttpResponseHandler.java

@@ -78,8 +78,16 @@ public MLSdkAsyncHttpResponseHandler(
     @Override
     public void onHeaders(SdkHttpResponse response) {
         SdkHttpFullResponse sdkResponse = (SdkHttpFullResponse) response;
+        List<String> errorsInHeader = sdkResponse.headers().get("x-amzn-ErrorType");
+        boolean containsThrottlingException = errorsInHeader.stream().anyMatch(str -> str.startsWith("ThrottlingException"));
         log.debug("received response headers: " + sdkResponse.headers());
         this.statusCode = sdkResponse.statusCode();
+        if (containsThrottlingException) {
+            throw new OpenSearchStatusException(
+                REMOTE_SERVICE_ERROR + "The request was denied due to request throttling.",
+                RestStatus.fromCode(statusCode)
+            );
+        }
     }
 
     @Override