[FLEDGE] Fix interest group API allowed check.

https://chromium-review.googlesource.com/c/chromium/src/+/3404766 added
a helper function so that all calls use the right frame origin
parameters, but introduced a bug where it would claim all operations
were a join. This CL fixes that.

Bug: 1289425
Change-Id: I87d5d551aa79786e0cac4672abed2affbd0dffc0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3415256


Commit-Queue: Matt Menke <mmenke@chromium.org>
Auto-Submit: Matt Menke <mmenke@chromium.org>
Reviewed-by: Theodore Olsauskas-Warren <sauski@google.com>
Commit-Queue: Theodore Olsauskas-Warren <sauski@google.com>
Cr-Commit-Position: refs/heads/main@{#963056}