Current File : //lib/systemd/system/grub-boot-indeterminate.service

[Unit]
Description=Mark boot as indeterminate
DefaultDependencies=false
Requires=sysinit.target
After=sysinit.target
Wants=system-update-pre.target
Before=system-update-pre.target

[Service]
Type=oneshot
ExecStart=/usr/bin/grub2-editenv - incr boot_indeterminate