RESTapi login issue

Question

I have the following login API.

public function login() {
        if (Auth::attempt(['email' => request('email'), 'password' => request('password')])) {
            $user = Auth::user();
            $success['token'] = $user->createToken('MyApp')->accessToken;
            $agency = new AgencyResource(Agency::find($user->agency_id));
            $success['agency'] = $agency;
            return response()->json(['responseCode' => '101', 'responseMessage' => 'Login successful', 'data' => $success], $this->successStatus);

        } else {
            return response()->json(['responseCode' => '102', 'responseMessage' => 'Invalid username or password', 'data' => null], 401);
        }
    }

Whenever I check in the postman with wrong credentials I get the following response.

{
    "responseCode": "102",
    "responseMessage": "Invalid username or password",
    "data": null
}

Which is correct. But the same api gives the following response on Android Device not in json format.

   Result in Failure:
[Failure: Exception : HTTP Exception 401 Unauthorized]

Question: I need to have response as what is given by postman. Please help

I use laravel 5.5