[iOS] Establish profile service used for Best of Google app promo

This CL creates a profile service that will be used to determine the
eligibility of the app bundle promo. Since the bulk of logic should be
impelemnted in `internal`. the factory currently does NOT return the
actual service.

Bug: 440148910
Change-Id: I5c7284058f29711866c653106ae79cc64ddc2432
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6873043
Reviewed-by: Mark Cogan <marq@chromium.org>
Auto-Submit: Ginny Huang <ginnyhuang@chromium.org>
Commit-Queue: Ginny Huang <ginnyhuang@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1505166}