Revert "[Tab Group Parity] Remove unbatching annotation on parity tests"

This reverts commit dc551af4.

Reason for revert: Possibly failing builds https://ci.chromium.org/ui/p/chrome/builders/ci/android-arm-tests

Original change's description:
> [Tab Group Parity] Remove unbatching annotation on parity tests
>
> Unbatching these tests is likely not the solution to the flakiness of
> modal dialog related parity tests, so removing them.
>
> Bug: 41490324
> Change-Id: I331f59a92b53f67c6ab49c35bd755e96d79f137c
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5405935


> Reviewed-by: Sky Malice <skym@chromium.org>
> Auto-Submit: Brandon Fong <bjfong@google.com>
> Commit-Queue: Brandon Fong <bjfong@google.com>
> Cr-Commit-Position: refs/heads/main@{#1279829}

Bug: 41490324
Change-Id: I8e0d5020486e683a270a4b891dfd007b6f4a1958
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5405460


Reviewed-by: Xi Han <hanxi@chromium.org>
Commit-Queue: Xi Han <hanxi@chromium.org>
Owners-Override: Xi Han <hanxi@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1279911}