[ios] Remove password generation from manual fallback

Following UX discussion, we are removing PG access from manual fallback in favor of
a better automatic flow.

Bug: 886583
Change-Id: I7bdd9f8f8f2a938efcd739be006142220b8fb28c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1523390
Reviewed-by: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Reviewed-by: Vadym Doroshenko <dvadym@chromium.org>
Commit-Queue: David Jean <djean@chromium.org>
Cr-Commit-Position: refs/heads/master@{#641533}
7 files changed