Add APK building to PR asset building and release pipelines

[rtibbles]

Summary

• Adds building of a release asset for all Kolibri releases which will get released to the internal testing track on the play store
• Adds promoting of internal testing track asset to open testing track for final releases
• Adds building and uploading of non-release APK files to PR assets

References

Integrates learningequality/kolibri-installer-android#152 into Kolibri

Reviewer guidance

The only real way to test the release part of this is to merge it, but please double check my yml.

PR build showing an APK should be a sign of success for the other part!

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Testing checklist

• Contributor has fully tested the PR manually
• If there are any front-end changes, before/after screenshots are included
• Critical user journeys are covered by Gherkin stories
• Critical and brittle code paths are covered by unit tests

PR process

• PR has the correct target branch and milestone
• PR has 'needs review' or 'work-in-progress' label
• If PR is ready for review, a reviewer has been added. (Don't use 'Assignees')
• If this is an important user-facing change, PR or related issue has a 'changelog' label
• If this includes an internal dependency change, a link to the diff is provided

Reviewer checklist

• Automated test coverage is satisfactory
• PR is fully functional
• PR has been tested for accessibility regressions
• External dependency files were updated if necessary (yarn and pip)
• Documentation is updated
• Contributor is in AUTHORS.md

[github-actions]

Build Artifacts

Asset type	Download link
PEX file	kolibri-0.16.0b2.dev0_git.7.g6ce164f5.pex
Windows Installer (EXE)	kolibri-0.16.0b2.dev0+git.7.g6ce164f5-unsigned.exe
Debian Package	kolibri_0.16.0b2.dev0+git.7.g6ce164f5-0ubuntu1_all.deb
Mac Installer (DMG)	kolibri-0.16.0b2.dev0+git.7.g6ce164f5-0.3.0.dmg
TAR file	kolibri-0.16.0b2.dev0+git.7.g6ce164f5.tar.gz
WHL file	kolibri-0.16.0b2.dev0+git.7.g6ce164f5-py2.py3-none-any.whl

[jredrejo]

Nothing to object on this PR changes, but it seems the build_apk workflow has a problem with a required dependency on setuptools

[rtibbles]

Yeah, I am making some tweaks on the other repo to fix up these issues.

[rtibbles]

This is now only failing because of permissions issues for the secrets I am referencing. I am pretty confident that this is good to merge.

[rtibbles]

Merging, on my own head be it if anything breaks.