如何制作圆形图标标记而不是常规形状？

Question

我正在尝试使常规图标标记成为圆形 这是我暂时的图标标记：

                                            int height = 85;
                                            int width = 85;
                                            Bitmap bmImg = Ion.with(navBarMainActivity.this).load(Conf.host+":"+Conf.port+"/storage/"+jo.getString("logo")).asBitmap().get();
                                            Bitmap smallMarker = Bitmap.createScaledBitmap(bmImg, width, height, false);
                                            Marker marker =mMap.addMarker( new MarkerOptions()
                                                    .title(jo.get("name").toString())
                                                    .position(new LatLng(latitude,longitude))
                                                    .snippet(CalculationByDistance(latitude,longitude,currentLocation.getLatitude(),currentLocation.getLongitude()))
                                                    .icon(BitmapDescriptorFactory.fromBitmap(smallMarker)));
                                            marker.setTag(jo.get("id").toString());

我想使图标变圆