[Typescript][Angular] formParams are not included as body in the request

[angelfraga]

Description

The generated code doesn't add formParams as body for files.

Swagger-codegen version

Current online typescript-angular generator.

Swagger declaration file content or url

openapi: 3.0.1
info:
  title: CSV import api 
  version: '1.0'
paths:
  /api/1/Import:
    post:
      tags:
        - CSV
      summary: Import a csv
      operationId: ImportCsv
      parameters:
        - name: X-Correlation-ID
          in: header
          schema:
            type: string
      requestBody:
        content:
          multipart/form-data:
            schema:
              type: object
              properties:
                file:
                  type: string
                  format: binary
            encoding:
              file:
                style: form
      responses:
        '200':
          description: Success
tags:
  - name: CSV
    description: 'Import a csv file'

Produces

       ....
        if (file !== undefined) {
            formParams = formParams.append('file', <any>file) as any || formParams;
        }
       // HERE   
        return this.httpClient.post<any>(`${this.basePath}/api/1/Import`,
            {
                withCredentials: this.configuration.withCredentials,
                headers: headers,
                observe: observe,
                reportProgress: reportProgress
            }
        );
       ....

Instead of

       ....
        if (file !== undefined) {
            formParams = formParams.append('file', <any>file) as any || formParams;
        }
        return this.httpClient.post<any>(`${this.basePath}/api/1/Import`,
            formParams, // as body
            {
                withCredentials: this.configuration.withCredentials,
                headers: headers,
                observe: observe,
                reportProgress: reportProgress
            }
        );
       ....

Command line used for generation

Online generator.