Enable filtering statistics by center in Chill configuration: set the default value in config

Set the default value in configuration file. This improves the readability of multiple options.

config/packages/chill.yaml

@@ -17,6 +17,7 @@ chill_main:
     acl:
         form_show_scopes: true
         form_show_centers: true
+        filter_stats_by_center: true
     access_global_history: false
     access_user_change_password: true
     access_permissions_group_list: true