Revert "WebAppService Crosapi: Expose MigrateLauncherState()"

This reverts commit 859a8c9bd051c7d780f2d465b9d81928b146c797.

Reason for revert: suspected to be test failure:
https://ci.chromium.org/ui/p/chromium/builders/ci/linux-chromeos-rel/67720/test-results?sortby=&groupby=

Original change's description:
> WebAppService Crosapi: Expose MigrateLauncherState()
>
> This CL:
> - Renames TransferAppAttributes() to MigrateLauncherState().
>   The old name was a copy paste of the implementation detail
>   of calling into AppListSyncableService::TransferItemAttributes().
> - Removes MigrateLauncherState() from non-ChromeOS platforms.
> - Exposes it over WebAppService crosapi to allow web apps
>   in Lacros to invoke the functionality inside the Ash process.
>
> Forked from: https://chromium-review.googlesource.com/c/chromium/src/+/4311502
>
> Bug: 1335299
> Change-Id: If7ae232ae24ade4ae7ccce569538cadd6eabf45b
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4653692
> Reviewed-by: Maggie Cai <mxcai@chromium.org>
> Reviewed-by: Roland Bock <rbock@google.com>
> Commit-Queue: Alan Cutter <alancutter@chromium.org>
> Reviewed-by: Glen Robertson <glenrob@chromium.org>
> Reviewed-by: Sam McNally <sammc@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#1170308}

Bug: 1335299
Change-Id: Ie0f3596f8d73bd9c5782ac9583fca01c54cb2914
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4686133
Owners-Override: Yoichi Osato <yoichio@chromium.org>
Commit-Queue: Yoichi Osato <yoichio@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Yoichi Osato <yoichio@chromium.org>
Auto-Submit: Yoichi Osato <yoichio@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1170358}