Track the latest release version more precisely for all products

[Iinh]

Currently, in Firefox products, if a metric has a version number as its expiry information, we compare it to the latest release version to determine if it has expired. This latest release info we pull from FIREFOX_PRODUCT_DETAIL_URL, which is an API that tracks Fx desktop major releases.

However, as Jan-Erik pointed out:

While mobile apps follow roughly the same schedule, they don't exactly match.

We should find more correct resources that better track the releases of Fx mobile, and other Glean products.