MM-61231 Fix Hidden Menus in System Roles Page (#28916)

* remove overflow:hidden to prevent cutting off menus in admin panels

* fix wrapping help text in system role permissions menu

webapp/channels/src/components/admin_console/system_roles/system_role/system_role_permissions.scss

@@ -116,6 +116,7 @@
                 .PermissionSectionDropdownOptions_description {
                     padding-bottom: 4px;
                     line-height: 16px;
+                    white-space: normal;
                 }
             }
         }

webapp/channels/src/components/widgets/admin_console/admin_panel.scss

@@ -1,7 +1,6 @@
 @import 'utils/variables';
 
 .AdminPanel {
-    overflow: hidden;
     padding: 0;
     border: solid 1px rgba(var(--center-channel-color-rgb), 0.12);
     border-radius: var(--radius-s);