fix(radio): prevent triggering click action on radio keyboard navigation

As click events propagates, triggering a click action on radio-button
creates potential side-effect (for instance, this will activate ripple
effect of parent container like md-list-item).

radio/lib/single-selection-controller.ts

@@ -216,8 +216,13 @@ export class SingleSelectionController implements ReactiveController {
       }
 
       // The next sibling should be checked, focused and dispatch a change event
+      nextSibling.checked = true;
       nextSibling.removeAttribute('tabindex');
-      nextSibling.click();
+      nextSibling.focus();
+      // Fire a change event since the change is triggered by a user action.
+      // This matches native <input type="radio"> behavior.
+      nextSibling.dispatchEvent(new Event('change', {bubbles: true}));
+
       break;
     }
   };