This is just code cleanup blocked on removing the "config server is coordinator" override, but would be easy and quick.

Rather than setting _initiatedCommit to true in each of

• TransactionRouter::_commitSingleShardTransaction
• TransactionRouter::_commitReadOnlyTransaction
• TransactionRouter::_commitMultiShardTransaction
• TransactionRouter::_commitWithRecoveryToken

it can just be set to true in TransactionRouter::commitTransaction. This is blocked on removing the "config server is coordinator" override, because the override checks _initiatedCommit inside TransactionRouter::_commitMultiShardTransaction and expects it to be false the first time commit is called.