[BUG] Query anonymization doesn't work in fallback log

[LantaoJin]

What is the bug?
Query anonymization is not working in the fallback log

How can one reproduce the bug?
Write a simple query and add ?format=json to trigger falling back to old engine.

POST /_plugins/_sql?format=json
{
  "query" : """
  SELECT min(DistanceMiles), avg(DistanceMiles), max(DistanceMiles)
    FROM opensearch_dashboards_sample_data_flights
      GROUP BY Carrier
  """
}

Or write a query which is unsupported in V2, e.g JOIN

POST /_plugins/_sql
{
  "query" : """
  SELECT s.FlightNum, s.OriginCityName, d.DestCityName
    FROM opensearch_dashboards_sample_data_flights s
      JOIN opensearch_dashboards_sample_data_flights d
        ON s.DestCityName = d.OriginCityName
  """
}

See this line in the logs

Request SQLQueryRequest(jsonContent={"query":"\n SELECT min(DistanceMiles),avg(DistanceMiles),max(DistanceMiles) FROM opensearch_dashboards_sample_data_flights GROUP BY Carrier\n "}, query=
SELECT min(DistanceMiles),avg(DistanceMiles),max(DistanceMiles) FROM opensearch_dashboards_sample_data_flights GROUP BY Carrier
, path=/_plugins/_sql, format=json, params={pretty=true, format=json}, sanitize=true, cursor=Optional.empty) is not supported and falling back to old SQL engine

Request SQLQueryRequest(jsonContent={"query":"\n SELECT s.FlightNum, s.OriginCityName, d.DestCityName FROM opensearch_dashboards_sample_data_flights s JOIN opensearch_dashboards_sample_data_flights d ON s.DestCityName = d.OriginCityName\n "}, query=
SELECT s.FlightNum, s.OriginCityName, d.DestCityName FROM opensearch_dashboards_sample_data_flights s JOIN opensearch_dashboards_sample_data_flights d ON s.DestCityName = d.OriginCityName
, path=/_plugins/_sql, format=jdbc, params={pretty=true}, sanitize=true, cursor=Optional.empty) is not supported and falling back to old SQL engine

What is the expected behavior?
Logs should show

Request SQLQueryRequest(query=
SELECT MIN ( identifier ), AVG ( identifier ), MAX ( identifier ) FROM table GROUP BY identifier
, path=/_plugins/_sql, format=json, params={pretty=true, format=json}, sanitize=true, cursor=Optional.empty) is not supported and falling back to old SQL engine

Request SQLQueryRequest(query=
SELECT identifier, identifier, identifier FROM table s JOIN table d ON identifier = identifier
, path=/_plugins/_sql, format=jdbc, params={pretty=true}, sanitize=true, cursor=Optional.empty) is not supported and falling back to old SQL engine

What is your host/environment?

• Version 2.15
• Plugins SQL

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Do you have any additional context?
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