mutation UpdateUserAccountType($accountType: UserAccountType!, $uid: String!) {
  updateUserAccountType(accountType: $accountType, uid: $uid) {
    ok
  }
}

{
  "accountType": "ADMIN",
  "uid": "string"
}

{
  "data": {
    "updateUserAccountType": {
      "ok": true
    }
  }
}