Pyarrow decimal256 being inferred as NUMERIC instead of BIGNUMERIC in bq data transfer

[Dulius]

I have a collection of parquet files that I need to upload to a bq table using the data transfer api. When I type my data for storage I use the following pyarrow field types in syc with bq types

```

{

            "STRING": pa.string(),

            "TIMESTAMP": pa.timestamp("ns"),

            "NUMERIC": pa.decimal128(precision=38, scale=9),

            "BIGNUMERIC": pa.decimal256(precision=76, scale=38),

            "DECIMAL": pa.decimal128(precision=38, scale=9),

            "BIGDECIMAL": pa.decimal256(precision=76, scale=38),

            "INTEGER": pa.int32(),

            "FLOAT": pa.float64(),

        }

```

My data is written to gcs using my pyarrow schema but then when my data transfer runs, I get the error:

Provided Schema does not match Table $table_uri. Field $field has changed type from BIGNUMERIC to NUMERIC; JobID: $job_id

For field $field of the destination table, my schema.json has the value: `

{"mode": "NULLABLE", "type": "BIGDECIMAL", "name": "$field"}`

Is there a way to define the type as BIGNUMERIC to avoid this error?