A 15-year-old boy was critically injured in a shooting near Six Flags Over Georgia, a popular amusement park in suburban Atlanta, after police exchanged gunfire with a group of people, authorities said Sunday.Cobb County Police Department officers were assisting with crowd control near the amusement park’s entrance on Saturday “after several fights had taken place” among people who were leaving the park, the Georgia Bureau of Investigation said in a press release.UNIVERSAL ORLANDO RELEASES DETAILS ABOUT THE EPIC UNIVERSE, THE PARK OPENING ITS DOORS NEXT YEAR”At some point, multiple people…