The city has agreed to pay $1.6 million to the family of a woman who was scared to death after cops mistakenly burst into her Harlem apartment and exploded a flash grenade in a bungled raid, it was announced yesterday. The deal settles a $500 million lawsuit filed in May by 57-year-old Alberta Spruill's two sisters and a niece. "While compensation cannot bring Ms. Spruill back, it nevertheless reflects the city's sorrow over her unintended and tragic death," said Corporation Counsel Michael Cardozo. Neither family members nor their attorney, former O.J. Simpson Dream Team lawyer Johnnie Cochran, could be reached...