fix(material-experimental/mdc-select): add list class to option (#23738)

* fix(material-experimental/mdc-select): add list class to option

* fix(material-experimental/mdc-menu): add list class to item

Author: andrewseguin

src/material-experimental/mdc-core/option/option.ts

@@ -41,7 +41,7 @@ import {MatOptgroup} from './optgroup';
     '[attr.aria-disabled]': 'disabled.toString()',
     '(click)': '_selectViaInteraction()',
     '(keydown)': '_handleKeydown($event)',
-    'class': 'mat-mdc-option mat-mdc-focus-indicator',
+    'class': 'mat-mdc-option mat-mdc-focus-indicator mdc-list-item',
   },
   styleUrls: ['option.css'],
   templateUrl: 'option.html',

src/material-experimental/mdc-menu/menu-item.ts

@@ -22,7 +22,7 @@ import {MatMenuItem as BaseMatMenuItem} from '@angular/material/menu';
     // classlist, but these should not be added for this MDC equivalent menu item.
     '[class.mat-menu-item]': 'false',
     '[class.mat-focus-indicator]': 'false',
-    'class': 'mat-mdc-menu-item mat-mdc-focus-indicator',
+    'class': 'mat-mdc-menu-item mat-mdc-focus-indicator mdc-list-item',
     '[class.mat-mdc-menu-item-highlighted]': '_highlighted',
     '[class.mat-mdc-menu-item-submenu-trigger]': '_triggersSubmenu',
     '[attr.tabindex]': '_getTabIndex()',