Remove ARC kiosk specific directories

This is the first step towards removing support for ARC Kiosk sessions,
since the last board that supported this is now EOL.

Bug: b/336756417
Change-Id: I3a2a8652124c31ffb64631251462756246aabf15
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5527061
Reviewed-by: Irina Fedorova <irfedorova@google.com>
Reviewed-by: Dominic Battre <battre@chromium.org>
Commit-Queue: Jeroen Dhollander <jeroendh@google.com>
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1301406}