On Ubuntu, scaling_governor becomes powersave after rebooted, even we configured cpufrequtils.
This is because ondemand.service, it unconditionally change scaling_governor to ondemand or powersave.
cpufrequtils will start before ondemand.service, scaling_governor overwrite by ondemand.service.
To configure scaling_governor correctly, we have to disable this service.
Fixes#9324Closes#9325