oneshot services causes boot failures due to lack of timeout

[gauravjuvekar]

nvidia-mig-manager.service is Type=oneshot.
DefaultTimeoutStartSec is not used for oneshot services, which causes the entire system to fail to boot stuck for nvidia-mig-manager.service to complete.

Boot failure is worse than a failed / degraded service.

A TimeoutStartSec should be added to this to at least allow the system to boot in a degraded state (for debug / recovery without OOB BMC / IPMI / KVM).

The root cause may be #11 , but a timeout addition will make this more resilient.