[iOS][Default Promo] Listen to first-party url opens for non-modal promo

This tracks first-party url scheme opens by looking for times when the
app is opened via a direct url with a scheme other than http/https. It
also verifies that the caller app is a first-party app.

Bug: 1191536
Change-Id: I9186e1db9d1c67c1e5e0e4cbbbd75aa6b0d34be0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2880536
Commit-Queue: Robbie Gibson <rkgibson@google.com>
Reviewed-by: Javier Flores <javierrobles@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#883522}