Publishes to a public track for the separate nightly app

[mitchhentges]

We published to the internal track while RelMan/QA/other teams performed all the verifications need to create the separate nightly app. Once the nightly app goes public, we should automatically publish new nightlies directly to the public track (beta, in this case).

Pull Request checklist

• Quality: This PR builds and passes detekt/ktlint checks (A pre-push hook is recommended)
• Tests: This PR includes thorough tests or an explanation of why it does not
• Accessibility: The code in this PR follows accessibility best practices or does not include any user facing features
• Firefox Preview Nightly is publicly released

[JohanLorenzo]

🚢 it!

[pocmo]

🚢

[liuche]

Great! I'm still waiting on relman to get this published, linking bugzilla here: https://bugzilla.mozilla.org/show_bug.cgi?id=1575728

[boek]

@liuche Is landing this blocked by relman?

[liuche]

Yep, this change stops publishing nightlies to the internal track - once we have the public channel, we want to land this so we stop publishing to that internal track.

[sblatz]

So this should have a "do not land" label?

@liuche

[codecov-io]

Codecov Report

Merging #4954 into master will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master    #4954   +/-   ##
=========================================
  Coverage     12.68%   12.68%           
  Complexity      275      275           
=========================================
  Files           251      251           
  Lines         10294    10294           
  Branches       1501     1501           
=========================================
  Hits           1306     1306           
  Misses         8897     8897           
  Partials         91       91

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[liuche]

We have the nightly channel available on Google Play now, so this can land, to start publishing to that public channel.

We have some smoketests for PI to make sure everything is working correctly.

[mitchhentges]

This UI test is taking its sweet time

[liuche]

omfg i know 😭

[JohanLorenzo]

Thanks for taking care of it @mitchhentges !