[wishlist] Increase Unity auto-hide default sensitivity

When I turn on auto-hide of Unity launcher, the default sensitivity of revealing the launcher is set very low. I need to bang on the edge of the window with the mouse to get the launcher back. Sometimes it works but the most of the time it doesn't. Simple remedy is to push up the reveal sensitivity to 90%-100%. The current default sensitivity is bad for user experience. It would be nice to have a sensible default reveal sensitivity in the future versions of Ubuntu after we turn on the auto-hide of Unity launcher.