I've never seen a Boeing Checklist which mandates an evacuation in response to a cargo, or indeed ANY fire indication. Your airline may teach it, but it is neither a Boeing, nor universal procedure at all airlines.
Wiz the following comes from your own companies B777 QRH checklist instructions/ non normal checklists.
It must be stressed that for smoke that continues or a fire that cannot be positively
confirmed to be completely extinguished, the earliest possible descent, landing,
and
evacuation must be done.