Instead of using a timestamp this will synchronize the Nightly version with the version
of Gecko / A-C. So when using 90.0.20210426143115 then the Nightly version will be
90.0a1 - similar to what Firefox desktop uses.
This PR builds on [AC##9024][1], and implements setting the Nimbus endpoints from [a secret set at build time][2].
For production use, this requires a secret named `nimbus_url` to be put into CI.
Note: Nimbus is currently behind a feature flag.
If developers wish to use a Nimbus server for local development, you can set the url by adding an entry into local.properties, e.g.:
```
nimbus.remote-settings.url=https://settings.stage.moz4ws.net
```
Without setting server, Nimbus will be able to function, except no experimental definitions will be fetched, and features under experiment will be configured as if not enrolled in the experiment.
[1]: https://github.com/mozilla-mobile/android-components/pull/9024
[2]: https://groups.google.com/a/mozilla.com/g/android-components-team/c/lAGVKQy8aiA/m/rY3uGAwhBAAJ
* For #3088: add translation pruning Py scripts from Focus
The only change made was updating "Focus/Klar" to "Fenix"
* For 3088: call translation pruning scripts during release builds
* For 3088: fix filter-release-translations.py
Moving it into Fenix introduced one additional layer of nesting, which was not accounted for in a relative path. 🤦
* For 3088: comment about the risks of modifying source
* For 3088: updated locales.py to read from l10n.toml
Also removed some previously unused properties from locales.py
* For 3088: added error handling to script in locales.py
* For 3088: updated locale parser per review comments
It was fixed in [1], but I regressed it when I resolved conflicts in [2]
[1] 9729fd494e\#diff-3a2aaafc93fc8bb53e2029001aa236aeL98
[2] 060e915d2b\#diff-3a2aaafc93fc8bb53e2029001aa236aeR95
