modify checkBox testcases

Signed-off-by: Nwang-xupeng2 <wangxupeng2@huawei.com>

arkui/ace_ets_component_ui/entry/src/main/ets/MainAbility/pages/checkBoxExample.ets

@@ -50,7 +50,7 @@ struct CheckboxExample {
           } else {
              this.selectedColor = "#000000"
           }
-        }).key('chek1')
+        }).id('chek1')
       Checkbox({name: 'checkbox2',  group: 'checkboxGroup'})
         .select(false)
         .selectedColor(0x39a2db)