Make Lao language available in the in app setting.

[bmarty]

Type of change

• Feature
• Bugfix
• Technical
• Other : new language added

Content

Lao translations are quite new. If the locale of the device is set to Lao, the translations will be used. This PR adds what's necessary to add this local to the in app language setting, so it's now possible to force using Lao.

Motivation and context

Screenshots / GIFs

Before	After

Tests

• Go to setting/Preferences/Language and select Lao. Observe that the UI is now displayed in Lao.

Tested devices

• Physical
• Emulator
• OS version(s):

Checklist

• Changes has been tested on an Android device or Android emulator with API 21
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com./vector-im/element-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./vector-im/element-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
• If you have modified the screen flow, or added new screens to the application, you have updated the test UiAllScreensSanityTest.allScreensTest()

[bmarty]

See https://www.unicode.org/iso15924/iso15924-codes.html

[github-actions]

Unit Test Results

142 files  ±0  142 suites  ±0   2m 19s ⏱️ -11s
229 tests ±0  229 ✔️ ±0  0 💤 ±0  0 ❌ ±0 
760 runs  ±0  760 ✔️ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit 9ed62ac. ± Comparison against base commit 483b1ab.

[github-actions]

Matrix SDK

Integration Tests Results:

• [org.matrix.android.sdk.session]
  = passed=20 failures=0 errors=0 skipped=3
• [org.matrix.android.sdk.account]
  = passed=3 failures=0 errors=0 skipped=2
• [org.matrix.android.sdk.internal]
  = passed=3 failures=0 errors=0 skipped=2
• [org.matrix.android.sdk.ordering]
  = passed=16 failures=0 errors=0 skipped=0
• [org.matrix.android.sdk.PermalinkParserTest]
  = passed=2 failures=0 errors=0 skipped=0