Revert "[Hub Toolbar] Update content description for 3-dot menu button"

This reverts commit bb7d2643c9549bdc262ed2c4c8a26a6a8ce666db.

Reason for revert: Causing CQ builds to fail with an "UnusedResources" lint warning: crbug.com/381299210

Original change's description:
> [Hub Toolbar] Update content description for 3-dot menu button
>
> This CL adds a new string for the content description (TalkBack) of
> the Tab Switcher 3-dot menu. It will help TalkBack users to
> differentiate the menu contents from other menus (e.g., the NTP
> 3-dot menu).
>
> Bug: 350775001
> Change-Id: Ifaa738dd86c77083ae5fe353bc4aeac2545697ab
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6056231
> Reviewed-by: Xi Han <hanxi@chromium.org>
> Commit-Queue: Dan Polanco <polardz@google.com>
> Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
> Reviewed-by: Calder Kitagawa <ckitagawa@chromium.org>
> Reviewed-by: Sky Malice <skym@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1389064}

Bug: 350775001, 381299210
Change-Id: I492dc96b1e58e0164fc73bbd247f38751e29dee0
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6056510
Owners-Override: Ian Wells <iwells@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Xi Han <hanxi@chromium.org>
Reviewed-by: Sky Malice <skym@chromium.org>
Auto-Submit: Ian Wells <iwells@chromium.org>
Reviewed-by: Calder Kitagawa <ckitagawa@chromium.org>
Reviewed-by: Frank Liberato <liberato@chromium.org>
Commit-Queue: Frank Liberato <liberato@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1389084}