Print UI polish.

1. Fixed an issue where input focus is given to the copies
   edit text every other time we expand the options UI. We
   want focus there only if the user touches the control.

   bug:16966145

2. Fixed the all printers list view to have item dividers
   reaching the left and right ends of the list view.

   bug:17288761

3. Fixed an issue where the user can deselect all pages
   which is not only an invalid state but also causes a crash.

   bug:17286198

4. Tweaked the minimal size of the preview in landscape on
   phone to better accomodate the page.

   bug:17288904

5. Fixed a regression introduced by a change from the UI folks.

Change-Id: Ida7dad7eea413295a840028060810b2619c616e8