In-app language preferences

[tonkku107]

Type of change

• Feature
• Bugfix
• Technical
• Other :

Content

Following up on #2795 this PR adds a language preferences section in-app behind a feature flag.

There is no icon for it at the moment because there was no suitable icon within the design system.

There are 2 new strings that would need to be added to localazy.

I couldn't add tests on the presenter because of the access to context and I wasn't sure how to proceed with that.

Motivation and context

Users of Android 12 or older would also like to change the language per-app and it turns out some OEMs are also hiding the system per-app language preferences on 13+.

Screenshots / GIFs

Tests

• Enable the feature flag in developer settings
• Open the new language section
• Test switching to different languages and back to default
• On >=13 check that the selection is also reflected on the system side
• On <=12 check that the language settings actually work and persist

Tested devices

• Physical
• Emulator
• OS version(s): 15 (beta 1.2), 12

Checklist

• Changes have been tested on an Android device or Android emulator with API 23
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/element-hq/element-x-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request includes a new file under ./changelog.d. See https://github.com/element-hq/element-x-android/blob/develop/CONTRIBUTING.md#changelog
• Pull request includes screenshots or videos if containing UI changes
• Pull request includes a sign off
• You've made a self review of your PR

[github-actions]

Thank you for your contribution! Here are a few things to check in the PR to ensure it's reviewed as quickly as possible:

• Your branch should be based on origin/develop, at least when it was created.
• There is a changelog entry in the changelog.d folder with the Towncrier format.
• The test pass locally running ./gradlew test.
• The code quality check suite pass locally running ./gradlew runQualityChecks.
• If you modified anything related to the UI, including previews, you'll have to run the Record screenshots GH action in your forked repo: that will generate compatible new screenshots. However, given Github Actions limitations, it will prevent the CI from running temporarily, until you upload a new commit after that one. To do so, just pull the latest changes and push an empty commit.

[codecov]

Codecov Report

Attention: Patch coverage is 60.00000% with 34 lines in your changes are missing coverage. Please review.

Project coverage is 73.96%. Comparing base (87bd3ee) to head (ca2dbb7).
Report is 2 commits behind head on develop.

Files	Patch %	Lines
...erences/impl/language/LanguageSettingsPresenter.kt	0.00%	28 Missing ⚠️
.../preferences/impl/language/LanguageSettingsView.kt	80.00%	0 Missing and 4 partials ⚠️
...tures/preferences/impl/root/PreferencesRootView.kt	75.00%	0 Missing and 1 partial ⚠️
...ries/featureflag/impl/StaticFeatureFlagProvider.kt	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2850      +/-   ##
===========================================
- Coverage    73.99%   73.96%   -0.03%     
===========================================
  Files         1531     1536       +5     
  Lines        36526    36611      +85     
  Branches      7065     7079      +14     
===========================================
+ Hits         27028    27081      +53     
- Misses        5796     5822      +26     
- Partials      3702     3708       +6     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[jmartinesp]

Thank you for the PR!

We just discussed this contribution with our product team and although the PR is quite well made we're not sure we want to support per-app language from inside the app or in older OS versions. We may come back to it later and decide to add this feature, but not right now, sorry.