H»rali SUM WrIUrGreater Miami police officials, confronted by disclosures that the Gold Coast again is wide open to gamblers, acknowledged Monday that bookies indeed have moved in.Top police officers of almost every Dade County municipality. meeting with State Attorney Richard Gerstein, promised an effort to clean up the spreading bookie rackets. They said they would add more men to their bookie squads.The Herald in two days last weekend pointed up the infiltration of gamblers by uncovering 12 hookmaking spotsin Miami and Miami Beach.* Hard on the heels of theexpose came a sudden flurry of developments Monday: