add changelog

Signed-off-by: bowenlan-amzn <[email protected]>

Author: bowenlan-amzn

CHANGELOG.md

@@ -40,6 +40,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Use Bad Request status for InputCoercionException ([#18161](https://github.com/opensearch-project/OpenSearch/pull/18161))
 - Null check field names in QueryStringQueryBuilder ([#18194](https://github.com/opensearch-project/OpenSearch/pull/18194))
 - Avoid NPE if on SnapshotInfo if 'shallow' boolean not present ([#18187](https://github.com/opensearch-project/OpenSearch/issues/18187))
+- Fix regex query from query string query to work with field alias ([#18215](https://github.com/opensearch-project/OpenSearch/issues/18215))
 
 ### Security