Include id to the error msg when it's too long (#49433)

Author: JaredTan95

server/src/main/java/org/elasticsearch/action/index/IndexRequest.java

@@ -198,7 +198,7 @@ public ActionRequestValidationException validate() {
         validationException = DocWriteRequest.validateSeqNoBasedCASParams(this, validationException);
 
         if (id != null && id.getBytes(StandardCharsets.UTF_8).length > 512) {
-            validationException = addValidationError("id is too long, must be no longer than 512 bytes but was: " +
+            validationException = addValidationError("id [" + id + "] is too long, must be no longer than 512 bytes but was: " +
                             id.getBytes(StandardCharsets.UTF_8).length, validationException);
         }
 

server/src/test/java/org/elasticsearch/action/index/IndexRequestTests.java

@@ -102,7 +102,7 @@ public void testIndexingRejectsLongIds() {
         validate = request.validate();
         assertThat(validate, notNullValue());
         assertThat(validate.getMessage(),
-                containsString("id is too long, must be no longer than 512 bytes but was: 513"));
+                containsString("id [" + id + "] is too long, must be no longer than 512 bytes but was: 513"));
     }
 
     public void testWaitForActiveShards() {