Split ManagedUserProfileNoticeHandler proceed_callback in 2

The proceed_callback used to handle the user choice and cleaning up
the UI view after the user choice was handled.
This is now split in a process_user_choice_callback and done_callback.

This change is to allow adding a user confirmation screen on the
interception flows after a profile has been created for OIDC signin.

The flow will change from:
OIDC signin -> Show managed dialog -> Create profile -> Close dialog
to
OIDC signin -> Show managed dialog -> Create profile -> Update dialog
text -> Close dialog.

This change does not affect existing managed non-OIDC sign in flows.

refactor, here the goal is to not break any existing tests.

Bug: 345733641
Change-Id: I45b93076a65311306927c26dfc811c257648c7b4
Low-Coverage-Reason: LARGE_SCALE_REFACTOR This CL is part of a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5598572


Commit-Queue: Yann Dago <ydago@chromium.org>
Reviewed-by: David Roger <droger@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1313029}