Interstitials without approvals for local content filtering

This is a basic version of the error page and doesn't offer the approval
flow. The new error is protected behind a new feature flag.

Bug: 425947410
Low-Coverage-Reason: EXPERIMENTAL_CODE trivial js only on Android
Change-Id: I2e391334da88e0b338678eb4485a6526d5dbbe71
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6650796
Commit-Queue: Tomek Jurkiewicz <tju@google.com>
Reviewed-by: David Roger <droger@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1476228}