SERVER-111411 refactored the code the validate timeseries shard key early in the flow and removed it from  resharding_util::createReshardingCoordinatorDoc.

The consequence of this is the following failure scenario in multiversion:

1. Old coordinator doesn't have early validation → sends invalid timeseries reshard key to config server.
2. New config server's createReshardingCoordinatorDoc() no longer validates timeseries keys and incorrectly validates the key.

We should readd this duplicate check until SERVER-111411 is backported till 8.0