app:launcher:: fix launcher cannot be shown problem on gala.

1. ensure launcher is not minimazed when shown.
2. set launcher to active window when shown.

tower: https://tower.im/projects/8f19f0bf0e754f0b82ef2c24bc230973/todos/1ee5a761584849c28318564316f2b1e1/

Change-Id: I55b28829e597e9219f4106b3cb6fd14c71bc5396