ISTWCMS-5879: fix warning when setting default value

uw_cfg_common.module

@@ -246,17 +246,17 @@ function uw_cfg_common_form_layout_builder_configure_section_alter(array &$form,
   // Column separator group should not appear one column.
   if (isset($form['layout_builder_style_column_separator'])) {
     // Ensuring that none is selected for column separator by default.
-    $form['layout_builder_style_column_separator']['#default_value']['uw_lbs_column_separator_none'] = 'uw_lbs_column_separator_none';
+    $form['layout_builder_style_column_separator']['#default_value'] = 'uw_lbs_column_separator_none';
   }
 
   // Ensuring that none is selected for section separator by default.
-  $form['layout_builder_style_section_separator']['#default_value']['uw_lbs_section_separator_none'] = 'uw_lbs_section_separator_none';
+  $form['layout_builder_style_section_separator']['#default_value'] = 'uw_lbs_section_separator_none';
 
   // Ensuring that default is selected for section spacing by default.
-  $form['layout_builder_style_section_spacing']['#default_value']['uw_lbs_section_spacing_default'] = 'uw_lbs_section_spacing_default';
+  $form['layout_builder_style_section_spacing']['#default_value'] = 'uw_lbs_section_spacing_default';
 
   // Ensuring that the contained width is selected by default.
-  $form['layout_builder_style_default']['#default_value']['uw_lbs_contained_width'] = 'uw_lbs_contained_width';
+  $form['layout_builder_style_default']['#default_value'] = 'uw_lbs_contained_width';
 }
 
 /**