recovery: Get UI and locale from device.

This removes some reliance on the global
locale and ui variables.

Test: Recovery works
Bug: 78793464
Change-Id: I78f1a2b321f5d50aa58b10735a73ae137283353a
diff --git a/screen_ui.h b/screen_ui.h
index fb811ce..3e391be 100644
--- a/screen_ui.h
+++ b/screen_ui.h
@@ -114,6 +114,7 @@
   explicit ScreenRecoveryUI(bool scrollable_menu);
 
   bool Init(const std::string& locale) override;
+  std::string GetLocale() override;
 
   // overall recovery state ("background image")
   void SetBackground(Icon icon) override;