message: In case of 400 error show the response body text to user (lib),
diff: @@ -5383,6 +5383,10 @@ error Context::pushEntries(
  trigger_sync_ = false;
  }
  + if (kBadRequestError == resp.err) {
  + error_message = resp.body;
  + }
  +
  continue;
  }
  