[XR] Exit FSM when the tab dropped outside of the Chrome window

On Android XR the Tab Switcher is only appears in Full Space mode (FSM).
When new Chrome window gets created as a result of a tab/group being
dropped outside of the Chrome window - we want to exit FSM in the source
window. This requires a small delay before a new window should be
created so the app has enough time to play transition animations and
switch spatial modes.

Bug: 399085135
Change-Id: I8f3e855b6434ae275384ccdeb52d0ca8329a0a8f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6583831
Reviewed-by: Neil Coronado <nemco@google.com>
Commit-Queue: Oleh Desiatyrikov (xWF) <desiatyrikov@google.com>
Reviewed-by: Calder Kitagawa <ckitagawa@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1468902}