[iOS] Add extra event to standard iOS Promo Configs

All standard promos should only show once per month, so add that rule
to all standard promo configs. Any config that does not require this
rule goes in the custom configs function, which should have a higher
bar to add to.

Bug: none
Change-Id: Icad43be0607c1990b054014f20645c88bf0a5bb9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4762145
Commit-Queue: Robbie Gibson <rkgibson@google.com>
Reviewed-by: Guillaume Jenkins <gujen@google.com>
Cr-Commit-Position: refs/heads/main@{#1181606}