fix: update MFE_CONFIG to use 'brandOverride' for theme URLs

Author: Ang-m4

plugins/tutor-contrib-paragon/tutorparagon/templates/paragon/settings/mfe-common-settings

@@ -2,7 +2,7 @@
 MFE_CONFIG["PARAGON_THEME_URLS"] = {
     "core": {
         "urls": {
-            "default": "{{ PARAGON_BASE_URL }}core/core.min.css"
+            "brandOverride": "{{ PARAGON_BASE_URL }}core/core.min.css"
         },
     },
     "defaults": {
@@ -13,7 +13,7 @@ MFE_CONFIG["PARAGON_THEME_URLS"] = {
     "variants": {
        {% for theme in PARAGON_ENABLED_THEMES %}"{{ theme }}": {
             "urls": {
-                "default": "{{ PARAGON_BASE_URL }}themes/{{ theme }}/{{ theme }}.min.css"
+                "brandOverride": "{{ PARAGON_BASE_URL }}themes/{{ theme }}/{{ theme }}.min.css"
             }
         },{% endfor %}
     }