overlay: Disable fading marquee

The framerate drops significantly when any comes on screen.

Before: http://winsuk.net/screens/p930/withfading.png
After: http://winsuk.net/screens/p930/withoutfading.png

Conflicts:
	overlay/frameworks/base/core/res/res/values/config.xml

Change-Id: I15449c8cae440287e3c2e19bf1f5850c33e15939