[gnome-shell] appDisplay: Add back background color for folder icons

[Florian Müllner <fmuellner src gnome org>]

commit 4d773a5ce91ff1cdb68fc5f7c2be3be0041638ee
Author: Jonas Dreßler <verdre v0yd nl>
Date:   Sun Feb 16 21:56:27 2020 +0100

    appDisplay: Add back background color for folder icons
    
    During this cycle the background color of the folder icons was removed
    (probably fallout from the theme refactor), this was not intended
    design-wise, so add it back.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/1011

 data/theme/gnome-shell-sass/widgets/_app-grid.scss | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/data/theme/gnome-shell-sass/widgets/_app-grid.scss 
b/data/theme/gnome-shell-sass/widgets/_app-grid.scss
index b23bea981b..1d2e135b44 100644
--- a/data/theme/gnome-shell-sass/widgets/_app-grid.scss
+++ b/data/theme/gnome-shell-sass/widgets/_app-grid.scss
@@ -35,9 +35,9 @@ $app_grid_fg_color: #fff;
 }
 
 /* App Folders */
-.app-folder {
-  .overview-icon {
-  }
+.app-well-app.app-folder {
+  background-color: transparentize($osd_bg_color, 0.8);
+  border-radius: $base_border_radius + 4px; // same as %icon_tile
 }
 
 // expanded folder