Update UT for older version

Signed-off-by: Sooraj Sinha <soosinha@amazon.com>

CHANGELOG.md

@@ -115,6 +115,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - Fix GRPC AUX_TRANSPORT_PORT and SETTING_GRPC_PORT settings and remove lingering HTTP terminology ([#17037](https://github.com/opensearch-project/OpenSearch/pull/17037))
 - Fix exists queries on nested flat_object fields throws exception ([#16803](https://github.com/opensearch-project/OpenSearch/pull/16803))
 - Use OpenSearch version to deserializat remote custom metadata([#16494](https://github.com/opensearch-project/OpenSearch/pull/16494))
+- Use OpenSearch version to deserialize remote custom metadata([#16494](https://github.com/opensearch-project/OpenSearch/pull/16494))
 
 ### Security
 

server/src/test/java/org/opensearch/gateway/remote/RemoteGlobalMetadataManagerTests.java

@@ -481,6 +481,12 @@ public void testGetAsyncWriteRunnable_TemplatesMetadata() throws Exception {
     }
 
     public void testGetAsyncReadRunnable_CustomMetadata() throws Exception {
+        for (Version version : List.of(Version.CURRENT, Version.V_2_15_0, Version.V_2_13_0)) {
+            verifyCustomMetadataReadForVersion(version);
+        }
+    }
+
+    private void verifyCustomMetadataReadForVersion(Version version) throws Exception {
         Metadata.Custom customMetadata = getCustomMetadata();
         String fileName = randomAlphaOfLength(10);
         RemoteCustomMetadata customMetadataForDownload = new RemoteCustomMetadata(
@@ -489,7 +495,7 @@ public void testGetAsyncReadRunnable_CustomMetadata() throws Exception {
             CLUSTER_UUID,
             compressor,
             namedWriteableRegistry,
-            Version.CURRENT
+            version
         );
         when(blobStoreTransferService.downloadBlob(anyIterable(), anyString())).thenReturn(
             customMetadataForDownload.customBlobStoreFormat.serialize(customMetadata, fileName, compressor).streamInput()
@@ -697,4 +703,5 @@ public void testGetUpdatedCustoms() {
         assertThat(customsDiff.getUpserts(), is(expectedUpserts));
         assertThat(customsDiff.getDeletes(), is(List.of(CustomMetadata1.TYPE)));
     }
+
 }