overlay: Disable fading marquee for a small speedup

Before: http://winsuk.net/screens/liberty/withfadingmarquee.png
After: http://winsuk.net/screens/liberty/withoutfadingmarquee.png

See "Enable Bluetooth HCI snoo-" in screenshots for what this change looks like

Change-Id: Ic0f895917def81d9fe91e524cfd4267bc0dd2152