Add experimental note

Author: avijeet95

databricks-sdk-java/src/main/java/com/databricks/sdk/core/commons/CommonsHttpClient.java

@@ -101,6 +101,8 @@ public Builder withConnectionManager(PoolingHttpClientConnectionManager connecti
     /**
      * @param requestRetryHandler the HttpRequestRetryHandler to use for the HttpClient.
      * @return This builder.
+     *     <p><b>Note:</b> This API is experimental and may change or be removed in future releases
+     *     without notice.
      */
     public Builder withRequestRetryHandler(HttpRequestRetryHandler requestRetryHandler) {
       this.requestRetryHandler = requestRetryHandler;