Add case to this part of CollectionImpl::checkValidation() to return Status::OK(). The donor shard primary is responsible for performing document validation. Consider adding a NamespaceString::isExemptedFromDocumentValidation() method to package up this special handler.

The goal is for the recipient shard primary to behave like a replica set secondary when performing operations on the "<database>.system.resharding.*" namespace. Secondaries use DisableDocumentValidation to skip doing document validation during oplog application. SERVER-48081 should be kept in mind for where expect to place the early return of Status::OK().