Lock Kiosk Next Home in landscape mode

Updates ScreenOrientationController to allow locking the home screen
window (normally it only checks for MRU windows, which intentionally
excludes the home screen).

Then updates KioskNextHomeController to add an orientation lock.

Bug: 951610
Change-Id: Ie932279eda9ca4a9cc4bb2325fc95b984affd025
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1612659
Commit-Queue: Michael Giuffrida <michaelpg@chromium.org>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#661428}
4 files changed