[User Education] Ensure correct histograms are emitted when IPH closes.

This is to ensure that when an IPH emits a kAbortPromo histogram value
(which is the fallback if no other close reason is given) it does not
correspond to some other result failing to be recorded; i.e. it ensures
that if, say, a promo was snoozed or dismissed, the correct histogram
value is emitted.

Change-Id: I3b8a022664bdbe85ef5af6bb574d718e8b6a364a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5467634


Reviewed-by: Mickey Burks <mickeyburks@chromium.org>
Commit-Queue: Dana Fried <dfried@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1291988}