Current RTAMO onboarding implementation lets RTAMO users enroll in nimbus experiments. See bug 1697793

We should change this behavior and exclude RTAMO users from firstrun onboarding experiments targeting , fix will need to check for attribution data and return early before retrieving content from Experiment Feature Config - window.AWGetFeatureConfig();

https://searchfox.org/mozilla-central/source/browser/components/newtab/content-src/aboutwelcome/aboutwelcome.jsx#113

The Bugbug bot thinks this bug should belong to the 'Firefox::Messaging System' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Let's explore how we can update firstrun nimbus targeting to exclude RTAMO users

With bug 1694257 landed, scope of this fix involves https://phabricator.services.mozilla.com/D106418#3523551

I've tried inverting the checks so that RTAMO runs first, with an early return.
https://share.firefox.dev/3rWvicQ <-- profiling results with RTAMO first

https://share.firefox.dev/2QiI4ob <--profiling results from m-c, for comparison

moving back to triage

https://analytics.amplitude.com/mozilla-corp/dashboard/1oxtf8i UJET Amplitude showing RTAMO numbers

We shouldn't need this if we're excluding this in code (by checking RTAMO attribution before checking experiment enrollment).

Fixed and verified in bug 1711700 comment 12
https://hg.mozilla.org/mozilla-central/rev/5cfa6f26806f