Comment 2 for bug 1588901

A note here, we shouldn't call it "power_updated_at" because that should be only filled when the power transition is done and not when it started. The "provision_updated_at" works for provision states because we have intermediate states such as DEPLOYING or DEPLOYWAIT and for power we don't have anything like POWERING_ON or REBOOTING.

I would suggest the new field to be called "power_transition_started_at".