Trebuchet: Further adjustment of panel overview glitch fix

 * These values takes care of the glitch also on legacy
   480x800 devices.

Change-Id: Ia901699351ed887a9100bbec6d10be9e92b50c14
Fix:

 - For devices with HW menu button, pressing menu in app tray doesn't show overview settings panel.
 - When you click the widgets button from the expanded settings pane, the settings pane eats touch events even when the workspace goes back into normal mode.

Change-Id: Ibf5f22c969f257ece72474c6ce91d7896aaba158