app/res:dock:: fix wrong hover image.

tower:https://tower.im/projects/8f19f0bf0e754f0b82ef2c24bc230973/todos/f97b680e2fec423fa650bd9c26acb94a/#6ba8130855714a8e9b75592a9f14f01f
Change-Id: I19590d54ffa68da279e560efc66193abb55319d3