Move SDLFileManager list files to a separate method
Move SDLFileManager list files to a separate method

smartdevicelink/sdl_ios,smartdevicelink/sdl_ios,APCVSRepo/sdl_ios,FordDev/sdl_ios,davidswi/sdl_ios,kshala-ford/sdl_ios,FordDev/sdl_ios,davidswi/sdl_ios,davidswi/sdl_ios,APCVSRepo/sdl_ios,FordDev/sdl_ios,APCVSRepo/sdl_ios,smartdevicelink/sdl_ios,APCVSRepo/sdl_ios,smartdevicelink/sdl_ios,kshala-ford/sdl_ios,FordDev/sdl_ios,APCVSRepo/sdl_ios,davidswi/sdl_ios,kshala-ford/sdl_ios,smartdevicelink/sdl_ios,davidswi/sdl_ios,kshala-ford/sdl_ios,kshala-ford/sdl_ios,FordDev/sdl_ios