Revert "Deflake DateTrayTest ShowTasksComboModel."

This reverts commit c982b31e.

Reason for revert:
GlanceablesV2/DateTrayTest.ShowTasksComboModel/1 is consistently
failing on linux-chromeos-chrome:
https://ci.chromium.org/ui/p/chrome/builders/ci/linux-chromeos-chrome/33091/overview

Original change's description:
> Deflake DateTrayTest ShowTasksComboModel.
>
> Bug: b:277268122
> Change-Id: If9f3215f0b4758ca5f9ca01f5d56f4c95d8d6b97
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4558348


> Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
> Reviewed-by: Toni Barzic <tbarzic@chromium.org>
> Commit-Queue: Yulun Wu <yulunwu@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1148694}

Bug: b:277268122
Change-Id: Ie45e6c993d2a4c6fc4808040dcc275cf508ae736
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4564814
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Owners-Override: Hiroki Nakagawa <nhiroki@chromium.org>
Commit-Queue: Hiroki Nakagawa <nhiroki@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1148913}