[ios] Prevent tab insertion animation during batch operation

Instead of checking whether the application is restoring a session,
disable the tab insertion animation during any batch operation. The
only batched operations that lead to inserting tabs are restoration
and moving tabs to the inactive Browser, both should not display an
animation.

Bug: 1383087
Change-Id: I8d09bf594433244fa05c0aac6aaf7d4101035e4b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4720969
Reviewed-by: Federica Germinario <fedegermi@google.com>
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1176009}