Create ServiceWorkerContainerHost mojo pipes in CommitResponse()

instead of creating them around `ServiceWorkerClient` construction.

`ScopedServiceWorkerClient` destructs `ServiceWorkerClient` in
its destructor synchronously, because it no longer depends on
disconnection detection on the mojo pipes.

Bug: 336154571
Change-Id: Ic07fcf24f8b78fa135554d4cb64589004de3d9f1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5549004


Reviewed-by: Yoshisato Yanagisawa <yyanagisawa@chromium.org>
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Commit-Queue: Hiroshige Hayashizaki <hiroshige@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1313612}