Miami-Dade’s requirement that David Beckham hire only county police and paramedics for his planned Miami soccer stadium drew more heat on Friday — including an indirect swipe from the county’s own fire chief. David Downey, head of Miami-Dade Fire and Rescue, signed a letter from a countywide chiefs association opposing any efforts by the county to “dictate” how rescue services are delivered within municipal jurisdictions. The statement by the Fire Officers Association of Miami-Dade came a day after Miami commissioners formally protested Miami-Dade including the demand as a condition of a $9 million land sale to the Beckham partnership earlier this week.