fixes from code review

Author: csviri

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/api/config/ConfigurationService.java

@@ -121,6 +121,9 @@ public HasMetadata clone(HasMetadata object) {
    * Retrieves the number of seconds the SDK waits for reconciliation threads to terminate before
    * shutting down.
    *
+   * @deprecated use {@link io.javaoperatorsdk.operator.Operator#stop(Duration)} instead. Where the
+   *             parameter can be passed regarding graceful timeout
+   *
    * @return the number of seconds to wait before terminating reconciliation threads
    */
   @Deprecated(forRemoval = true)