Getting different response in Volley and Postman

Question

I am using current code for volley request. However, I am getting different response in postman and on response.

RequestQueue queue = Volley.newRequestQueue(this);

            StringRequest strRequest = new StringRequest(Request.Method.POST, url,
                    new Response.Listener<String>()
                    {
                        @Override
                        public void onResponse(String response) {
                            Log.e("RESPONSE === ",response);
                        }
                    },
                    new Response.ErrorListener()
                    {
                        @Override
                        public void onErrorResponse(VolleyError error)
                        {

                        }
                    })
            {
                @Override
                protected Map<String, String> getParams()
                {
                    Map<String, String> params = new HashMap<String, String>();
                    params.put(getString(R.string.accessKeyForApi), SingleTonModel.accesskey);
                    return params;
                }
            };

            queue.add(strRequest);

What i am getting from Postman is:

[
    {
        "sectionHeader": "Today",
        "data": []
    },
    {
        "sectionHeader": "1 day ago",
        "data": [
            {
                "id": "3",
                "symbol_name": "EURUSD",
                "order_open_price": "1.20366",
                "signal_trading": "STRONG (--)",
                "date_time": "2018-01-11 21:37:48",
                "ticket": "79053141"
            },
            {
                "id": "2",
                "symbol_name": "EURUSD",
                "order_open_price": "1.20331",
                "signal_trading": "STRONG",
                "date_time": "2018-01-11 20:15:03",
                "ticket": "79053141"
            }
        ]
    },
    {
        "sectionHeader": "2 day ago",
        "data": []
    }
]

What I am getting in Log in Android studio

E/RESPONSE ===: {"0":{"sectionHeader":"Today","data":[]},"1":{"sectionHeader":"1 day ago","data":[]},"2":{"sectionHeader":"2 day ago","data":[]}}

I have added all permissions and also referred the link and here. I am unable to find the cause, can anyone tell me what I missed.