Don't send loading state updates from the network service to the browser on Android.

These are only used by desktop UI.

Bug: 1425174
Change-Id: I0a234e710a8edaaa2ad8d528efae15ee9cc95982
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4347657


Reviewed-by: Theresa Sullivan <twellington@chromium.org>
Commit-Queue: John Abd-El-Malek <jam@chromium.org>
Auto-Submit: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Theresa Sullivan <twellington@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1118440}