Trebuchet: fix expanded desktop with GEL integration

On leaving the GEL activity, we were setting extra flags, which affected
global sensitivity. We actually don't have to do any extra cleanup and
unset any flags, so let's just remove the code!

Change-Id: I111f2e4c62017841e0148f7172ad097e00962385
Signed-off-by: Roman Birg <roman@cyngn.com>