[SxS] Disable drag and drop on Wayland

There are bugs with the DoDrop never being called on Wayland. While we
investigate we are disabling this so users don't get a buggy version of
the feature. This will all be deleted when and if the bug can be fixed.

Bug: 425715421
Change-Id: I082f18410855fe1efb296ab6956b65389ee7bcaa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6675863
Reviewed-by: Eshwar Stalin <estalin@chromium.org>
Commit-Queue: Alison Gale <agale@chromium.org>
Reviewed-by: Kaan Alsan <alsan@chromium.org>
Reviewed-by: Kramer Ge <fangzhoug@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1479499}