@Override
    public boolean onJsPrompt(WebView view, String url, String message, String defaultValue,
        JsPromptResult result) {
      currentAlertMessage.add(message == null ? "null" : message);
      SelendroidLogger.info("new prompt message: " + message);
      if (callSuper) {
        return super.onJsPrompt(view, url, message, defaultValue, result);
      }
      return false;
    }
Unconventional way of adding a Javascript interface but the main reason why I took this way
is that it is working stable compared to the webview.addJavascriptInterface way.
selendroid-server/src/main/java/io/selendroid/server/model/SelendroidWebDriver.java