3scale - Unable to create or update choices in a fields definition using 3scale API

Issue

• When going through the 3scale API to create a fields definition, it creates the fields definition with all of the attributes specified, but the "choices" array always comes back empty, despite providing an array of choices.
• Trying to update an existing fields definition with an array of choices provided has the same behaviour -- the updated fields definition has an empty choices array.

• Following is the curl statement generated:

  curl -v  -X PUT "https://<your-admin-portal-url>/admin/api/fields_definitions/123456.json" -d 'access_token=<REDACTED>&target=Account&label=By+signing+up%2C+I+agree+to+the+following+Terms+and+Conditions&required=true&hidden=false&read_only=false&position=14&choices%5B%5D=%22%22&choices%5B%5D=%22Yes%22'
  

• Resulting in the following response:

  {
      "fields_definition": {
          "id": 123465,
          "target": "Account",
          "name": "terms_and_conditions",
          "label": "By signing up, I agree to the following Terms and Conditions",
          "required": true,
          "hidden": false,
          "read_only": false,
          "choices": [],
          "position": 14,
          "created_at": "2021-08-25T00:42:14Z",
          "updated_at": "2021-08-25T01:36:43Z"
      }
  }