grub menu cannot be hidden when other OS exist

[Wang Xuancong]

In /etc/default/grub, despite of setting the following options:
GRUB_DEFAULT=0
GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=0
GRUB_TIMEOUT_STYLE=hidden

as long as another OS exists, GRUB menu will always be displayed during boot.

The reason is because when OS prober is enabled, update-grub will forcefully insert the following 4 lines under session ### BEGIN /etc/grub.d/30_os-prober ### :
set timeout_style=menu
if [ "${timeout}" = 0 ]; then
  set timeout=10
fi

These nullifies options set in /etc/default/grub.

What I want is that I know there are multiple OS in my computer, but unless I press ESC during boot, I do not want to see the grub menu and wait for the countdown.