* Proposes a schedule change, once the block that contains the proposal becomes irreversible, the schedule is promoted to "pending" automatically. Once the block that promotes the schedule is irreversible, the schedule will become "active"
* @param producer_data - packed data of produce_keys in the appropriate producer schedule order
* @param producer_data_size - size of the data buffer
* @param serialized_transaction - Pointer of serialized transaction to be deferred
* @param size - Size to reserve
* @param replace_existing - f this is `0` then if the provided sender_id is already in use by an in-flight transaction from this contract, which will be a failing assert. If `1` then transaction will atomically cancel/replace the inflight transaction