Update "System Account" docs to reflect error code when transferring HBARs to reserved accounts

The System Accounts Operations _§ Transfer and send operations_ https://github.com/hiero-ledger/hiero-consensus-node/blob/main/hedera-node/docs/system-accounts-operations.md#transfer-and-send-operations document lists the errors that occur when an HBAR transfer is made to a reserved account.

It indicates that the error when transferring HBARs to addresses in the range [0x0, 0x2EE] (with the exception of HTS 0x167 for `tokenCreate`) is `INVALID_FEE_SUBMITTED`. However, PR https://github.com/hiero-ledger/hiero-consensus-node/pull/14186 introduced the following: "Change the response code returned when trying to transfer value to a system account from `INVALID_FEE_SUBMITTED` to `INVALID_CONTRACT_ID`"

This should be reflected in the docs to avoid confusion and make it clear this is intended behavior.

Open hedera-node/docs/system-accounts-operations.md at the Transfer and send operations section, then compare its reserved-account error table with PR #14186. Update the documented response code for [0x0, 0x2EE] while preserving the HTS 0x167 tokenCreate exception, and verify the section reflects the intended behavior.

Written by the indexing model from the issue text.