Enable strict ip enforcement by default

What does this MR do and why?

This MR enables strict_ip_enforcement by default. We're deploying it disabled for SaaS delivery reasons, but as soon as the deployment is finished we would like to quickly test it out and ship the restriction as more-secure by default in %15.10, with the flag for an SM users who wish to opt out for some continuity reason.

Global Rollout Issue: #391997 (closed) ✅

Steps

I've added verification steps, including enabling this flag by default, to #391997 (closed)

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.