Add mock modem service operations in Telephony

    /** Check if telephony new data stack is enabled. */

    boolean isUsingNewDataStack();

    /**

     *  @return true if the modem service is set successfully, false otherwise.

     */

    boolean setModemService(in String serviceName);

    /**

     * @return the service name of the modem service which bind to.

     */

    String getModemService();

}