Add captcha detection JetStream Outcome

[FKLC]

Hello,

We would like to add our captcha detection metrics to the experimenter. I think this covers it, but I'll be able to fix issues with it.

Do note that this depends on https://phabricator.services.mozilla.com/D262592.

Thank you!

[FKLC]

Just to be clear, I'm no longer a Mozilla employee. If there are legal or other implications, the next best contact for this whole thing is Tom Ritter.

[mikewilli]

Tagging @tomrittervg since @FKLC indicated that they no longer work at Mozilla. This PR looks stale and it's not clear to me whether you'd like to proceed with getting it merged.

If you do want to get it merged, there are some issues to address before merging (or in a follow-up) in order to make these metrics appear in Experimenter as an outcome, and to make them work with jetstream for analysis. I can provide guidance there if needed.

[tomrittervg]

Yes, this is still something we wish to pursue

[mikewilli]

Ok, there are two main things missing from this PR.

First, in order for these metrics to be made available to Experimenter, they need to be added to a new outcome. Outcomes are defined in the jetstream/outcomes folder grouped underneath the relevant app folder. You can keep the metric definitions in the definitions/firefox_desktop.toml file and then create a new file (e.g., jetstream/outcomes/firefox_desktop/captcha_detection.toml) that references them. https://github.com/mozilla/metric-hub/blob/main/jetstream/outcomes/firefox_desktop/sponsored_tiles.toml is an example of this.

And second, for the metrics to be useful to jetstream for analysis, you need to attach statistics to each metric. Statistics take the many observations about each client and turn them into more useful population-level information. The link I provided above also serves as an example of how these might be configured.

For more info:

• https://experimenter.info/deep-dives/jetstream/outcomes
• https://experimenter.info/deep-dives/jetstream/statistics