[BUG] COUNT with aggregation return multiple rows with null value about sql HOT 2 OPEN

 curl -X POST "http://localhost:9200/_plugins/_sql?format=jdbc" -H "Content-Type: application/json" -d '{
>   "query": "SELECT count(*) FROM test100 where status != 200"}'
{
  "schema": [
    {
      "name": "count(*)",
      "type": "integer"
    }
  ],
  "datarows": [
    [
      1
    ]
  ],
  "total": 1,
  "size": 1,
  "status": 200

curl -X POST "http://localhost:9200/_plugins/_sql?format=jdbc" -H "Content-Type: application/json" -d '{
>   "query": "SELECT count(*) FROM test100 where ImageType != \"machine\""
> }'
{
  "error": {
    "reason": "Error occurred in OpenSearch engine: all shards failed",
    "details": "Shard[0]: java.lang.IllegalArgumentException: Text fields are not optimised for operations that require per-document field data like aggregations and sorting, so these operations are disabled by default. Please use a keyword field instead. Alternatively, set fielddata=true on [ImageType] in order to load field data by uninverting the inverted index. Note that this can use significant memory.\n\nFor more details, please send request for Json format to see the raw response from OpenSearch engine.",
    "type": "SearchPhaseExecutionException"
  },
  "status": 400

 curl -X POST "http://localhost:9200/_plugins/_sql?format=json" -H "Content-Type: application/json" -d '{
>   "query": "SELECT count(*) FROM test100 where ImageType != \"machine\""
> }'
{
  "error": {
    "reason": "Invalid SQL query",
    "details": "Unsupported operation: !=",
    "type": "SqlParseException"
  },
  "status": 400
}

curl -X GET "http://localhost:9200/test200/_mapping"
{"test200":{"mappings":{"properties":{"ImageType":{"type":"keyword"}}}}} 

 curl -X POST "http://localhost:9200/_plugins/_sql?format=jdbc" -H "Content-Type: application/json" -d '{
>   "query": "SELECT count(*) FROM test200 where ImageType != \"machine\""}'
{
  "schema": [
    {
      "name": "count(*)",
      "type": "integer"
    }
  ],
  "datarows": [
    [
      1
    ]
  ],
  "total": 1,
  "size": 1,
  "status": 200
}