Revert "[Remote Commands] Add browser restart command"

This reverts commit ffe31cd19e923d4afbfc614c43b167b1fd866445.

Reason for revert: https://ci.chromium.org/ui/p/chromium/builders/ci/Linux%20ASan%20LSan%20Tests%20(1)/134620/overview

Bug: b/422128890
Original change's description:
> [Remote Commands] Add browser restart command
>
> When received, this command simply calls chrome::AttemptRestart(). To
> avoid the "restart loop" problem, Chrome only performs a restart if the
> command is more recent than the browser process.
>
> This can still break in some cases (clock drift, timezone change) and
> cause restart loops. A follow-up CL will add extra safeguards.
>
> Bug: b/422128890
> Change-Id: I32acf0caea01965688733ed78333c9bf05b665c1
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6595009
> Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
> Reviewed-by: Igor <igorcov@chromium.org>
> Reviewed-by: Owen Min <zmin@chromium.org>
> Commit-Queue: Nicolas Ouellet-Payeur <nicolaso@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1478647}

Bug: b/422128890
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Change-Id: Ided1ee1b65299955eed00991787ca732dbd785ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6675625
Auto-Submit: Dale Curtis <dalecurtis@chromium.org>
Owners-Override: Ben Pastene <bpastene@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Reviewed-by: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1478801}