refactor: 💡 uncomment on click handler for dropdown component (#2061)

* refactor: 💡 uncomment on click handler for dropdown component

* test: 💍 fix test

addons/core/addon/components/dropdown/index.hbs

@@ -13,7 +13,7 @@
     @color='secondary'
     @text={{@name}}
     @count={{@checkedItems.length}}
-    {{!-- {{on 'click' this.open}} --}}
+    {{on 'click' this.open}}
   />
   {{#if @isSearchable}}
     <DD.Header @hasDivider={{true}}>

addons/core/tests/integration/components/dropdown/index-test.js

@@ -78,7 +78,7 @@ module('Integration | Component | dropdown/index', function (hooks) {
   test('it calls applyFilter with the correct arguments', async function (assert) {
     assert.expect(1);
     this.set('applyFilter', (selectedItems) => {
-      assert.deepEqual(selectedItems, ['2']);
+      assert.deepEqual(selectedItems, ['1', '2']);
     });
 
     await render(hbs`<Dropdown