iwa: Test that cross-origin delegated permissions don't inherit IWA capabilities

This extends IsolatedWebAppUsbBrowserTest.ClaimInterface to test that
non-IWA main frames and cross-origin IWA iframes can access normal
USB devices but not devices from a protected class. IWA frames should
be allowed to access both.

Bug: b/280497768
Change-Id: I5b1b37830de32c72a5af779ef8d979e6e34a693a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4563661


Commit-Queue: Robbie McElrath <rmcelrath@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1149228}