[AUTO] [main] Added bwc version 2.3.1. (#4513)

* Added bwc version 2.3.1
* Add changelog of adding bwc version 2.3.1

Signed-off-by: Tianli Feng <ftianli@amazon.com>

.ci/bwcVersions

@@ -51,4 +51,5 @@ BWC_VERSION:
   - "2.2.1"
   - "2.2.2"
   - "2.3.0"
+  - "2.3.1"
   - "2.4.0"

CHANGELOG.md

@@ -16,6 +16,8 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Update previous release bwc version to 2.4.0 ([#4455](https://github.com/opensearch-project/OpenSearch/pull/4455))
 - 2.3.0 release notes ([#4457](https://github.com/opensearch-project/OpenSearch/pull/4457))
 - Added missing javadocs for `:distribution:tools` modules ([#4483](https://github.com/opensearch-project/OpenSearch/pull/4483))
+- Add BWC version 2.3.1 ([#4513](https://github.com/opensearch-project/OpenSearch/pull/4513))
+
 ### Dependencies
 - Bumps `reactive-streams` from 1.0.3 to 1.0.4
 

server/src/main/java/org/opensearch/Version.java

@@ -98,6 +98,7 @@ public class Version implements Comparable<Version>, ToXContentFragment {
     public static final Version V_2_2_1 = new Version(2020199, org.apache.lucene.util.Version.LUCENE_9_3_0);
     public static final Version V_2_2_2 = new Version(2020299, org.apache.lucene.util.Version.LUCENE_9_3_0);
     public static final Version V_2_3_0 = new Version(2030099, org.apache.lucene.util.Version.LUCENE_9_3_0);
+    public static final Version V_2_3_1 = new Version(2030199, org.apache.lucene.util.Version.LUCENE_9_3_0);
     public static final Version V_2_4_0 = new Version(2040099, org.apache.lucene.util.Version.LUCENE_9_3_0);
     public static final Version V_3_0_0 = new Version(3000099, org.apache.lucene.util.Version.LUCENE_9_4_0);
     public static final Version CURRENT = V_3_0_0;