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

res/values-sw600dp-land/dimens.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2011 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<resources>
+    <dimen name="screen_margin_sides">128dip</dimen>
+</resources>