See:
Incident: Ryanair B738 near Munich on Apr 4th 2018, wheel well fire indication
It would be wiser to assume it was a real fire and to get on to the ground asap. Holding for 15 minutes to read checklists with the fire warning still on, seems the height of poor airmanship. Some will remember the Swissair MD11 fatal accident where the crew delayed too long reading checklists and dumping fuel following smoke in the cockpit and crashed.
See:
https://en.wikipedia.org/wiki/Swissair_Flight_111
Lesson being you don't stuff around when there is indication of fire and smoke in the air. The priority is to land before you risk incapacitation.