Fix per-app locale handling across contexts (#6047)

Use AndroidX and framework per-app locale APIs, migrate the existing language preference, and expose the generated locale config to Android 13+ settings.

Resolve resources through the selected app locale in application, ViewModel, tile, and service contexts. Replace the framework OK and Cancel labels directly implicated in the wrong-language report, and refresh retained localized UI state after locale changes.

V2rayNG/app/src/main/res/values/strings.xml

@@ -8,6 +8,8 @@
     <string name="navigation_drawer_close">Close navigation drawer</string>
     <string name="migration_success">Data migration success!</string>
     <string name="action_stop_service">Stop service</string>
+    <string name="action_ok">OK</string>
+    <string name="action_cancel">Cancel</string>
     <string name="migration_fail">Data migration failed!</string>
     <string name="pull_down_to_refresh">Please pull down to refresh!</string>