Reland "[PrivacyPolicy] Deflake privacy policy related tests"

This reverts commit e9b287b92de67870791b63f789ff49cedf545906.

Reason for revert: Fixes tests, need to approve new screenshots
https://chrome-gold.skia.org/detail?grouping=name%3DBrowserUiDialog_PrivacySandboxDialogViewPrivacyPolicyBrowserTest_InvokeUi_PrivacyPolicy_crrev.com_c_6391455_windows%26source_type%3Dgtest-pixeltests&digest=c9ce78861e75ed3557c53c9a2f75fd0c old tests
were failing because they were disabled and had no images to compare
against

Bug: 371041180, 415305952
Original change's description:
> Revert "[PrivacyPolicy] Deflake privacy policy related tests"
>
> This reverts commit a51ff7fa0957cc5936555ca78b70eb443ff9f8c6.
>
> Reason for revert: Tests are consistently failing on gardened bots
>
> Bug: 371041180, 415305952
> Original change's description:
> > [PrivacyPolicy] Deflake privacy policy related tests
> >
> > - Privacy policy page may open without fully loading due to change
> > in loading happening after clicking the expand
> > - replacing the src to load the content of the test url may happen after
> > the screenshot is taken
> >
> > The previous test loads an error page, change this to load an
> > instantaneous empty page instead.
> >
> > Bug: 371041180, 415305952
> > Change-Id: Iaa44a9174226f284b55197a78063bc01ef03cdad
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6520071
> > Reviewed-by: Jacob Stanley <jacobstanley@google.com>
> > Reviewed-by: Abe Boujane <boujane@google.com>
> > Commit-Queue: Christine Ying <chrstne@google.com>
> > Cr-Commit-Position: refs/heads/main@{#1458238}
>
> Bug: 371041180, 415305952
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Change-Id: Ie8d85c76ddd7112973584400360af699da06f57b
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6534569
> Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
> Owners-Override: Noah Rose Ledesma <noahrose@google.com>
> Commit-Queue: Noah Rose Ledesma <noahrose@google.com>
> Cr-Commit-Position: refs/heads/main@{#1458393}

Bug: 371041180, 415305952
Change-Id: I6771d60c87f406f773cb3c6e0d0cf11d04bccd9a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6535290
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Abe Boujane <boujane@google.com>
Commit-Queue: Christine Ying <chrstne@google.com>
Reviewed-by: Jacob Stanley <jacobstanley@google.com>
Cr-Commit-Position: refs/heads/main@{#1459398}