GitLab

Renames AppListTabletModeContainer to HomeScreenContainer to reflect
that it contains the home screen (either app list or kiosk next app).

Hosts the KioskNextHome app window in this container when KioskNextShell
is enabled.

Also moves KioskNextShell tests from LoginUtilsTest to their own file.

Bug: 937549
Change-Id: Icd2a878ed67a913128058e3d5fe688b65de7c5ed
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1538688Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Michael Giuffrida <michaelpg@chromium.org>
Auto-Submit: Michael Giuffrida <michaelpg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#644371}