Create request via REST API is allowing to set reporter as Request Participant

Summary

It's currently possible to set reporter as Request Participant via REST API.

Environment

• CLOUD 3.3.0-OD-1000.564.0
• REST API 1000.445.0
• REST API latest - https://docs.atlassian.com/jira-servicedesk/REST/cloud/#servicedeskapi

Steps to Reproduce

1. Run the following call on your instance ( set the reporter as one of the request participants)

   https://INSTANCE.atlassian.net/rest/servicedeskapi/request
   {
       "serviceDeskId": "2",
       "requestTypeId": "16",
       "requestFieldValues": {
           "summary": "Request JSD help via REST 2",
           "description": "I need a new mouse for my Mac"
       },
       "requestParticipants": [
           "user1",
         	"MyReporter"
       ]
   }

Expected Results

The ticket should not get created because it's not possible to set a reporter as request participant. A similar message should return:

{"errorMessage":"Sorry, but the following usernames could not be added as participant to this request: MyReporter","i18nErrorMessage":{"i18nKey":"sd.request.participants.username.error","parameters":["MyReporter"]}}

Actual Results

The ticket is created successfully and the reporter is set into the request participant list.

Notes:

Via UI it's not possible to add reporter into the request participant's list.

Workaround

None so far.