Drawn of polylines in Google Maps Api

I have managed to trace the routes on the map, what I want to achieve is that the union between the polylines is rounded, or that there are no sharp cuts between strokes.

Stroke achieved:

Stroke to which you wish to arrive:

public void onDrawRoutes(final GoogleMap mMap) throws JSONException {

    final JSONArray polyline = mArray.getJSONObject(mRoute).getJSONArray("legs").getJSONObject(0).getJSONArray("steps");

    new AsyncTask<Void, Void, Void>() {
        @Override
        protected Void doInBackground(Void... params) {
            for (int i = 0; i < polyline.length(); i ++) {
                String points = null;
                try {
                    points = polyline.getJSONObject(i).getJSONObject("polyline").getString("points");
                } catch (JSONException e) {
                    e.printStackTrace();
                }
                lists.add(i, PolyUtil.decode(points));
            }
            return null;
        }

        @RequiresApi(api = Build.VERSION_CODES.M)
        @Override
        protected void onPostExecute(Void aVoid) {
            for (int j = 0; j < lists.size(); j++) {
                List<LatLng> iterable = lists.get(j);
                mMap.addPolyline(new PolylineOptions()
                        .addAll(iterable)
                        .width(20)
                        .color(mContext.getResources().getColor(R.color.ligthBlue, null)).geodesic(true));
            }
        }
    }.execute();

}