Fix incorrect error when cancelling pin request

Previously, the UI could not distinguish between a failed log in attempt
and the user cancelling the attempt. By saving that the user cancelled
the request, we suppress the error that would otherwise be displayed.

Fixed: 1045029
Change-Id: I758d2934db7da7206d13b6036c0723677ada33ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2017351
Commit-Queue: Fabian Sommer <fabiansommer@google.com>
Reviewed-by: Maksim Ivanov <emaxx@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#738164}

• ash/login/login_screen_controller.cc[diff]
• ash/login/login_screen_controller.h[diff]
• ash/login/ui/login_auth_user_view.cc[diff]
• ash/public/cpp/login_types.h[diff]