I never had the parentheses on GRUB_TIMEOUT or GRUB_TIMEOUT_STYLE.
GRUB_CMDLINE_LINUX_DEFAULT="quiet apparmor=1 security=apparmor udev.log_priority=3"
# If you want to enable the save default function, uncomment the following
# line, and set GRUB_DEFAULT to saved.
# Preload both GPT and MBR modules so that they are not missed
# Uncomment to enable booting from LUKS encrypted devices
# Uncomment to use basic console
# Uncomment to disable graphical terminal
# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command 'videoinfo'
# Uncomment to allow the kernel use the same resolution used by grub
# Uncomment if you want GRUB to pass to the Linux kernel the old parameter
# format "root=/dev/xxx" instead of "root=/dev/disk/by-uuid/xxx"
# Uncomment to disable generation of recovery mode menu entries
# Uncomment and set to the desired menu colors. Used by normal and wallpaper
# modes only. Entries specified as foreground/background.
# Uncomment one of them for the gfx desired, a image background or a gfxtheme
# Uncomment to get a beep at GRUB start
#GRUB_INIT_TUNE="480 440 1"