Remove extra styles on loading-container

loading-container is implementation detail of GlLoadingIcon
We should pass extra class to control styling

ee/app/assets/javascripts/environments/components/deploy_board_component.vue

@@ -98,7 +98,7 @@ export default {
 </script>
 <template>
   <div class="js-deploy-board deploy-board">
-    <gl-loading-icon v-if="isLoading" />
+    <gl-loading-icon v-if="isLoading" class="loading-icon" />
     <template v-else>
       <div v-if="hasLegacyAppLabel" class="bs-callout bs-callout-warning mb-0 mt-0">
         <span v-html="legacyLabelWarningMessage"></span>

ee/app/assets/javascripts/related_items_tree/components/tree_item.vue

@@ -96,7 +96,11 @@ export default {
       >
         <icon :name="chevronType" />
       </gl-button>
-      <gl-loading-icon v-if="childrenFlags[itemReference].itemChildrenFetchInProgress" size="sm" />
+      <gl-loading-icon
+        v-if="childrenFlags[itemReference].itemChildrenFetchInProgress"
+        class="loading-icon"
+        size="sm"
+      />
       <tree-item-body
         class="tree-item-row"
         :parent-item="parentItem"

ee/app/assets/stylesheets/components/related_items_tree.scss

@@ -48,7 +48,7 @@
       margin-left: $gl-sidebar-padding;
     }
 
-    .loading-container {
+    .loading-icon {
       margin-left: $gl-padding-4 / 2;
       margin-right: $gl-padding-4;
     }

ee/app/assets/stylesheets/pages/environments.scss

@@ -5,7 +5,7 @@
   background-color: $gray-light;
   min-height: 20px;
 
-  > .loading-container,
+  > .loading-icon,
   > .deploy-board-empty,
   > .deploy-board-information {
     padding: 10px;