Disable automatic grub update when booted into a snapshot #390
Description
As my comment in #320, timeshift creates a snapshot named 'before restoring' automatically right before restoring, which triggers grub-btrfsd and overwrites the kernel and initramfs path in grub.cfg to be the current booted snapshot. I'm using a merged /boot layout (/boot merged into /) but from #320 it seems like the issue is just universal. Snapper doesn't create one so things are just fine. While we can poke the timeshift developers for a switch for that behavior, I think it is a general better practice to not update grub when inside a snapshot at all.