Notification icons: Correctly apply color filter for DrawableContainers

        // Also, the notification might have been modified during the animation, so background

        // might be null here.

        if (iconDrawable != null) {

            iconDrawable.mutate().setColorFilter(mIconColorFilter);

            Drawable d = iconDrawable.mutate();

            // DrawableContainer ignores the color filter if it's already set, so clear it first to

            // get it set and invalidated properly.

            d.setColorFilter(null);

            d.setColorFilter(mIconColorFilter);

        }

    }