Chris Brown is back in court for his battle with his former housekeeper -- who claims she was viciously mauled by a dog outside his L.A. home -- days after drama erupted in the case. We got the singer as he walked into the courthouse Thursday for day one of his trial against Maria Avila ... he had few words for our photog, but his expressions when she asked him questions provided all the answers. As TMZ first reported ... the trial was scheduled to start earlier this week, but a mistrial was