What is the bug?

Queries that rename the group-by fields to their original field names will report errors when Calcite is enabled:

source=time_test | stats count() by span(value, 2000) as value
source=time_test | stats count() by span(timestamp, 1h) as timestamp

The error reports something like field [field_name] not found, input fields are [field_name0, ...]

{
  "error": {
    "reason": "Invalid Query",
    "details": "field [value] not found; input fields are: [value0, count()]",
    "type": "IllegalArgumentException"
  },
  "status": 400
}

This prohibits queries like by field_name span=xxx, where the output field name remains the same with the original field (field_name in this case).

How can one reproduce the bug?

POST /_plugins/_ppl
{
  "query" : "source=time_test | stats count() by span(value, 2000) as value"
}

What is the expected behavior?

The query can be executed when Calcite is disabled:

Output:

{
  "schema": [
    {
      "name": "count()",
      "type": "bigint"
    },
    {
      "name": "value",
      "type": "int"
    }
  ],
  "datarows": [
    [
      49,
      6000
    ],
    [
      51,
      8000
    ]
  ],
  "total": 2,
  "size": 2
}

What is your host/environment?

• OS: macOS
• Version: 3.3.0
• Plugins

Do you have any additional context?
Add any other context about the problem.