[Desktop] Attach necessary data to the plus address HaTS survey.

This CL attaches following time delta data to the plus address HaTS
survey:
* The time since the user has created the first plus address. This value
is -1 if this timestamp wasn't recorded for the user. This can happen if
the user has created the first plus address by the time the sync pref
was added to Chrome.
* The time since the last plus address filling event. This value is -1
if this event was not recorded for the user.

Bug: 348139343
Change-Id: I67c6802579c2e43c13ec15b90c5f157d50174927
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5979969
Reviewed-by: Jan Keitel <jkeitel@google.com>
Reviewed-by: Rubin Deliallisi <rubindl@chromium.org>
Reviewed-by: Dominic Battré <battre@chromium.org>
Commit-Queue: Timofey Chudakov <tchudakov@google.com>
Cr-Commit-Position: refs/heads/main@{#1378874}