Settings: add custom language/locale chooser (SDK33+).

Corsican was not available using Android's per-app-language-chooser.

Fixes #1974.

src/main/res/values/settings.xml

@@ -278,6 +278,9 @@
     <string name="settings_ui_dynamic_colors_key" translatable="false">uiDynamicColors</string>
     <bool name="settings_ui_dynamic_colors_default" translatable="false">false</bool>
 
+    <!-- androidx.appcompat.app.AppCompatDelegate.setDefaultNightMode() -->
+    <string name="locale_key" translatable="false">localeKey</string>
+
     <!-- androidx.appcompat.app.AppCompatDelegate.setDefaultNightMode() -->
     <string name="night_mode_key" translatable="false">nightMode</string>
     <string name="night_mode_default" translatable="false">@string/night_mode_system_value</string>

src/main/res/values/strings.xml

@@ -370,6 +370,9 @@ limitations under the License.
     <string name="settings_recording_track_name_number_option">Number</string>
     <string name="settings_recording_track_name_title">Default track name</string>
     <string name="settings_recording_idle_timeout_title">Idle threshold</string>
+    <string name="settings_locale_title">Language</string>
+    <string name="settings_locale_system_default">System default</string>
+
     <string name="settings_night_mode_title">UI Theme</string>
     <string name="settings_night_mode_option_system">System</string>
     <string name="settings_night_mode_option_day">Day</string>

src/main/res/xml/settings_user_interface.xml

@@ -4,6 +4,12 @@
     xmlns:app="http://schemas.android.com/apk/res-auto"
     android:title="@string/settings_ui_title">
 
+    <de.dennisguse.opentracks.settings.LocalePreference
+        android:key="@string/locale_key"
+        android:persistent="false"
+        android:title="@string/settings_locale_title"
+        app:useSimpleSummaryProvider="true" />
+
     <ListPreference
         android:defaultValue="@string/night_mode_default"
         android:entries="@array/night_mode_options"