Method to decode polyline points in Java. Credit goes to https://jeffreysambells.com/2010/05/27/decoding-polylines-from-google-maps-direction-api-with-java

DecodePoly.java

//Calling decodePoly
String polyline = (String)((JSONObject)((JSONObject)jSteps.get(k)).get("polyline")).get("points");
List<LatLng> list = decodePoly(polyline);

/*
where "polyline" & "points" are JSON key return from GoogleMap URl.
*/

// deocdePoly implementation  
private List<LatLng> decodePoly(String encoded) {

        List<LatLng> poly = new ArrayList<>();
        int index = 0, len = encoded.length();
        int lat = 0, lng = 0;

        while (index < len) {
            int b, shift = 0, result = 0;
            do {
                b = encoded.charAt(index++) - 63;
                result |= (b & 0x1f) << shift;
                shift += 5;
            } while (b >= 0x20);
            int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
            lat += dlat;

            shift = 0;
            result = 0;
            do {
                b = encoded.charAt(index++) - 63;
                result |= (b & 0x1f) << shift;
                shift += 5;
            } while (b >= 0x20);
            int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
            lng += dlng;

            LatLng p = new LatLng((((double) lat / 1E5)),
                    (((double) lng / 1E5)));
            poly.add(p);
        }

        return poly;
    }

Thank you sir. This solution worked for me