make setup wizard's wifi and datetime settings look good for 7"

Note: this entailed locking datetime settings not into portrait
like everything else in the setup process, but landscape, because
the existing xlarge layout wasn't rearranging itself into a portrait
alignment very well. I can give it another try later if I can have
some help from UE.

Change-Id: Ia8ce8e8292ed768bd117beedf3d94a287e658f4b