Configure resource folders for different device sizes

- This CL purely ports over changes from HC MR2 for 7" support
over to master (no new changes).
https://android-git.corp.google.com/g/#change,110633
https://android-git.corp.google.com/g/#change,110840

- In general:
  * phone layouts should go into the regular layout and values folders
  * 7" and tablet layouts should go into the sw580dp folders
    (meaning that the layouts only apply to devices with at least a
    minimum width in both orientations of 580dp)
  * if you want to exclude portrait on a 7" but include landscape on
    a 7", portrait and landscape on a 10" tablet, the layout
    should go into the sw580dp-w720dp (minimum screen width of 580dp
    with the current orientation being > 720dp)
  * if you only want landscape on a 10" tablet, then layouts should
    go into sw580dp-w1000dp (minimum screen width of 580dp with
    current orientation > 1000dp)

- TODO: Still need extensive testing in all the diff device sizes and
specific tweaks (i.e. to the action bar), but having the right folders
will help us be able to make UI changes isolated to one screen size

Bug: 4689448
Change-Id: I32f8df14854d68ab2fc98e21b7a18fc8f0df0000
42 files changed