The correct answer is neither.
A 50 kW DCFC can only provide max 50 kW. It can't deliver 55 kW.
The Bolt EV on a 50 kW DCFC will receive about 44-45 kW in the 0%-50% SOC battery range, if the amperage of the station is 125A (or about 35-37 kW if the amperage of the station is 100A). It will deliver less than 11 kW if you are charging the Bolt EV in the 95-100% SOC range.