OptionalportChange if port generation is enabled or not.
If enabled and a port is set, that port is tried, if locked a new one will be generated. If disabled and a port is set, only that port is tried, if locked a error will be thrown. If disabled and no port is set, will act as if enabled.
This setting will get overwritten by start's forceSamePort parameter if set
Extra Instance options specifically for MongoMemoryServer