Don't resubmit executor service for query manager on retries

Signed-off-by: Taylor Gray <tylgry@amazon.com>

Author: graytaylor0

data-prepper-plugins/opensearch/src/main/java/org/opensearch/dataprepper/plugins/sink/opensearch/OpenSearchSink.java

@@ -249,7 +249,7 @@ private void doInitializeInternal() throws IOException {
     openSearchClientRefresher = new OpenSearchClientRefresher(
             pluginMetrics, connectionConfiguration, clientFunction);
 
-    if (queryExecutorService != null) {
+    if (queryExecutorService != null && existingDocumentQueryManager == null) {
       existingDocumentQueryManager = new ExistingDocumentQueryManager(openSearchSinkConfig.getIndexConfiguration(), pluginMetrics, openSearchClient);
       queryExecutorService.submit(existingDocumentQueryManager);
     }