screen_ui: Drop the parameter in CheckBackgroundTextImages.

ScreenRecoveryUI already has the info in locale_.

Also when showing "Current locale: X/Y" on screen, use 1-based index for
X, so that we have 1 <= X <= Y.

Test: Build anf flash recovery image on aosp_bullhead-userdebug. Choose
      `Run locale test` from UI.
Change-Id: I5dd4de82e63890ddf755f4e23cd2290ad5d50ece
diff --git a/recovery.cpp b/recovery.cpp
index 01dce07..6aceb2d 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -897,7 +897,7 @@
 
       case Device::RUN_LOCALE_TEST: {
         ScreenRecoveryUI* screen_ui = static_cast<ScreenRecoveryUI*>(ui);
-        screen_ui->CheckBackgroundTextImages(screen_ui->GetLocale());
+        screen_ui->CheckBackgroundTextImages();
         break;
       }
       case Device::MOUNT_SYSTEM: