message: Fix expiration_timestamp key in generate_raw_txn_preburn.json
  Closes:
diff: "gas_unit_price": 0,
  "gas_currency_code": "LBR",
  "chain_id": "TESTING",
  - "expiration_timestamp": 1593189628
  + "expiration_timestamp_secs": 1593189628
  },
  "script_params": {
  "preburn": {
  