res:launcher:: change the background of category.

tower:https://tower.im/projects/8f19f0bf0e754f0b82ef2c24bc230973/todos/72ae707bcf0d451b9d80e2350189f58d/#2c783ad512dc4ad7bb4ff8f34131624d
Change-Id: Iec1620ab12aa544ade0f5ba01fb033820c6ed5fc