Bump AC version to 27.0.4 for 3.1 (mozilla-mobile#7582)

Update to use Mozilla Android Components 27.0.3. (mozilla-mobile#7542)

Use Android Components 24.0.1 with Fenix 3.0.2 (mozilla-mobile#7541)

* Update to Mozilla Android Components 24.0.1.

* Temporarily fix lint issues with bad translation of string (mozilla-mobile#6963)

Co-authored-by: Mihai Adrian <[email protected]>

Feature/mozilla-mobile#220 language menu (mozilla-mobile#7070)

* For mozilla-mobile#220
- Added advanced header + locale settings item in the settings fragment

* For mozilla-mobile#220
- Added locale selection page with lib state + handling of locale changes

* For mozilla-mobile#220
- Removed registering for locale changes in the manifest, allow system
to restart activity in that scenario

* For mozilla-mobile#220
- Added unit tests for locale settings page

* For mozilla-mobile#220: fixed an outdated unit test
ga-a

Co-authored-by: Severin Rudie <[email protected]>

Feature/mozilla-mobile#220 language menu (mozilla-mobile#7070)

* For mozilla-mobile#220
- Added advanced header + locale settings item in the settings fragment

* For mozilla-mobile#220
- Added locale selection page with lib state + handling of locale changes

* For mozilla-mobile#220
- Removed registering for locale changes in the manifest, allow system
to restart activity in that scenario

* For mozilla-mobile#220
- Added unit tests for locale settings page

* For mozilla-mobile#220: fixed an outdated unit test
ga-a

Co-authored-by: Severin Rudie <[email protected]>

For mozilla-mobile#6917 Emit mode change only when new mode is differ…

…ent from current

For mozilla-mobile#1607 - Passes "custom" as the search engine identi…

…fier for custom engines

Issue mozilla-mobile#6302 - Pin AC to 24.0.0 for 3.0 release. (mozill…

…a-mobile#6983)

Import l10n.

Change hypens to underscores in ic_launcher_round.png (mozilla-mobile…

…#6505)