HALO: batch message icon for hdpi and mdpi

It's hard to keep up with Paul hehe
HALO: fix the integer division bug

The newHeight is calculated by an integer division, which leads to an
ugly bug. E.g. a 95x96 image will get a newHeight of 0 because
(95 / 96 * 113) equals to 0. This will lead to a SystemUI FC.

Fix it by multipling first and dividing afterwards.