Authentication cookie will never expire by default after HADOOP-12049

// AuthenticationFilter

public static void createAuthCookie(HttpServletResponse resp, String token,
                                    String domain, String path, long expires,
                                    boolean isCookiePersistent,
                                    boolean isSecure) {
  //...
  //By default, isCookiePersistent = false
  if (expires >= 0 && isCookiePersistent) {
    Date date = new Date(expires);
    SimpleDateFormat df = new SimpleDateFormat("EEE, " +
            "dd-MMM-yyyy HH:mm:ss zzz");
    df.setTimeZone(TimeZone.getTimeZone("GMT"));
    sb.append("; Expires=").append(df.format(date));
  }

  //...
}