Currently, the `config.settings` collection contains a document describing the balancer configuration with three fields: mode, running, and activeWindow. In previous versions, there were multiple modes for the balancer when it was running, but now there are only two modes in total: "full", which means the balancer is running, and "off", which means the balancer is not running. This implies that the running value will always be "false" when the mode is "off" and always "true" when the mode is "full".

To reduce redundancy in the balancer configuration information, the running field should be removed from the `config.settings` collection.

Note: This change requires FCV upgrade/downgrade adjustments.