This CL maintains the DT Token metrics precedence over the global
allowlist grace period rollback behavior

The test changes allows for the
ThirdPartyCookieAllowMechanism::kAllowByTopLevel3PCD and
ThirdPartyCookieAllowMechanism::kAllowBy3PCD related grants to be
checked and recorded in the histogram, which was previously skipped
for specific cases such as when the grace period is forced on. And
checking the histogram here serves as a positive signal to the expected
behavior.

(cherry picked from commit 46a8486884a10833fd1e6ff329cf8a1883c7af05)

Bug: b:339830242
Change-Id: I4909fd717b1303af5e401056472dbcd326abf234
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5531826
Reviewed-by: Anton Maliev <amaliev@chromium.org>
Reviewed-by: Dylan Cutler <dylancutler@google.com>
Commit-Queue: Jonathan Njeunje <njeunje@chromium.org>
Cr-Original-Commit-Position: refs/heads/main@{#1299321}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5537180
Reviewed-by: Christian Dullweber <dullweber@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Anton Maliev <amaliev@chromium.org>
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Christian Dullweber <dullweber@chromium.org>
Auto-Submit: Jonathan Njeunje <njeunje@chromium.org>
Cr-Commit-Position: refs/branch-heads/6422@{#1017}
Cr-Branched-From: 9012208d0ce02e0cf0adb9b62558627c356f3278-refs/heads/main@{#1287751}