Disable session restore in BrowsingDataRemoverBrowserTest

This test needs to disable session restore to function properly. Session
restore is not on by default, usually, but in some configurations it is.
For example, Lacros enabled session restore by default, and for this
reason the test used to disable session restore. But Lacros was removed,
and the test's workaround was removed. Session restore can still be
enabled by default via an ongoing experiment (which is enabled on bots
via testing/variations/fieldtrial_testing_config.json) so this
workaround is relevant once again.

Fixed: 499382189
Change-Id: Ia6264eee71e1a919bccf9b59a4c7b240fc92f1ec
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7760365
Commit-Queue: Evan Stade <evanstade@microsoft.com>
Reviewed-by: Christian Dullweber <dullweber@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1614566}