apps.yaml validation error: car_charging_battery_size

[DJBenson]

The validator is saying that my value for car_charging_battery_size should be a sensor yet the documentation says;

car_charging_battery_size - Set this value in apps.yaml to the car's battery size in kWh which must be entered with one decimal place, e.g. 50.0. If not set, Predbat defaults to 100.0kWh. This will be used to predict when to stop car charging.

and my value is set to 77.4 (fixed value, not a sensor, as no such sensor exists).