The second attempt after SERVER-32051 was reverted, because it didn't work if the replica set was started using a config file with the 'replSetName' option.
Docs for SERVER-32105: Require shard servers and config servers to be started with --replSet or 'replSetName'
Require --shardsvrs not started in queryable backup mode to be started as replica sets
Require shard servers and config servers to be replica sets
Requiring replSet for shards breaks Queryable Backup
Update ShardingTest to default to starting shard servers as single-node replica sets rather than standalones