DYN-6364 Skip Lucene indexing process in UIless mode (#14523)

* skip Lucene indexing process in UIless mode

* Update comments

Author: QilongTang

src/DynamoCore/Models/DynamoModel.cs

@@ -160,8 +160,8 @@ internal LuceneSearchUtility LuceneUtility
 
         /// <summary>
         /// Flag to indicate that there is no UI on this process, and things
-        /// like the update manager and the analytics collection should be
-        /// disabled.
+        /// like the node index process, update manager and the analytics collection 
+        /// should be disabled.
         /// </summary>
         public static bool IsHeadless { get; set; }
 

src/DynamoCore/Utilities/LuceneSearchUtility.cs

@@ -106,6 +106,8 @@ internal LuceneSearchUtility(DynamoModel model, LuceneStartConfig config)
         /// </summary>
         internal void InitializeLuceneConfig()
         {
+            if (DynamoModel.IsHeadless) return;
+
             addedFields = new List<string>();
 
             DirectoryInfo luceneUserDataFolder;