Revert "Merge ChromeOS and other platforms allowlist for Incognito tests."

This reverts commit 73d3958d.

Reason for revert: caused failure on linux-chromeos-rel (e.g. https://ci.chromium.org/ui/p/chromium/builders/ci/linux-chromeos-rel/51337/overview)

Original change's description:
> Merge ChromeOS and other platforms allowlist for Incognito tests.
>
> User directory for tests on ChromeOS has a different name from other
> platforms resulting in redundancy in the allow-list.
> The list for all platform is updated to have a place holder for the user
> directory and redundant items are removed.
>
> Bug: 1234755
> Change-Id: Ida24e2378fa9e437e3cc03661e3a15152b57f236
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3172631


> Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
> Reviewed-by: David Roger <droger@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#923314}

Bug: 1234755
Change-Id: Ib44660c9ca7c95b38a7fbc9dad4c81c4c2ab430c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3172789
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
Commit-Queue: Elizabeth Popova <lizapopova@google.com>
Owners-Override: Elizabeth Popova <lizapopova@google.com>
Cr-Commit-Position: refs/heads/main@{#923359}