Make org.springframework.data.elasticsearch.client.elc.ReactiveElast…

…icsearchTemplate.ClientCallback public.

Original Pull Request #2815
Closes #2814

(cherry picked from commit 260dadd)

src/main/java/org/springframework/data/elasticsearch/client/elc/ReactiveElasticsearchTemplate.java

@@ -620,7 +620,7 @@ public BaseQueryBuilder queryBuilderWithIds(List<String> ids) {
 	 *
 	 * @param <T>
 	 */
-	interface ClientCallback<T extends Publisher<?>> {
+	public interface ClientCallback<T extends Publisher<?>> {
 
 		T doWithClient(ReactiveElasticsearchClient client);
 	}