Chris Brown testified Thursday he was “in shock” when he discovered a housekeeper lying face down outside his Los Angeles home, severely injured after being mauled by a massive security dog on his property five years ago. Taking the stand Thursday for the first time at a civil trial in Van Nuys, Calif., Brown acknowledged some responsibility for Maria Avila’s injuries that day but denied owning the Central Asian Ovcharka, named Hades, that attacked her. The singer claimed the rare breed had