Android: Use Android button layout for the DialogButtonBoxLayout hint

Fixes: QTBUG-70045
Change-Id: I9c51e9a769f510a6f14f6e9d78583caf3df15031
Reviewed-by: BogDan Vatra <bogdan@kdab.com>

src/plugins/platforms/android/qandroidplatformtheme.cpp

@@ -488,6 +488,8 @@ QVariant QAndroidPlatformTheme::themeHint(ThemeHint hint) const
 
             Q_FALLTHROUGH();
     }
+    case DialogButtonBoxLayout:
+        return QVariant(QPlatformDialogHelper::AndroidLayout);
     default:
         return QPlatformTheme::themeHint(hint);
     }