fix issue with loading icon appearing on top of down chevron

app/assets/javascripts/projects/gke_cluster_dropdowns/components/dropdown_button.vue

@@ -44,6 +44,7 @@ export default {
     <i
       aria-hidden="true"
       data-hidden="true"
+      v-show="!isLoading"
       class="fa fa-chevron-down"
     ></i>
   </button>