[Wayland] Fix XDG window activation regression

This fixes a regression after [1].  To activate windows after the
initial activation token is used, we need to request a new token.

[1] https://chromium-review.googlesource.com/c/chromium/src/+/5280365

Fixed: 338101162
Change-Id: I9183f96f000c0512b871065a76633da2e334d044
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5656700
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Auto-Submit: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Nick Yamane <nickdiego@igalia.com>
Cr-Commit-Position: refs/heads/main@{#1321373}