Switch feature flag from store to mixin

Switch to using the glFeatureFlag mixin instead of
setting it in the store.

app/assets/javascripts/vue_merge_request_widget/components/mr_widget_pipeline_container.vue

@@ -4,6 +4,7 @@ import ArtifactsApp from './artifacts_list_app.vue';
 import Deployment from './deployment.vue';
 import MrWidgetContainer from './mr_widget_container.vue';
 import MrWidgetPipeline from './mr_widget_pipeline.vue';
+import glFeatureFlagsMixin from '~/vue_shared/mixins/gl_feature_flags_mixin';
 
 /**
  * Renders the pipeline and related deployments from the store.
@@ -23,6 +24,7 @@ export default {
     MergeTrainPositionIndicator: () =>
       import('ee_component/vue_merge_request_widget/components/merge_train_position_indicator.vue'),
   },
+  mixins: [glFeatureFlagsMixin()],
   props: {
     mr: {
       type: Object,
@@ -62,7 +64,7 @@ export default {
       return this.isPostMerge ? this.mr.mergePipeline : this.mr.pipeline;
     },
     showVisualReviewAppLink() {
-      return this.mr.visualReviewAppAvailable && this.mr.visualReviewFF;
+      return this.mr.visualReviewAppAvailable && this.glFeatures.anonymousVisualReviewFeedback;
     },
     showMergeTrainPositionIndicator() {
       return _.isNumber(this.mr.mergeTrainIndex);

ee/app/assets/javascripts/vue_merge_request_widget/stores/mr_widget_store.js

@@ -31,7 +31,6 @@ export default class MergeRequestStore extends CEMergeRequestStore {
     this.canDismissVulnerability = Boolean(this.createVulnerabilityFeedbackDismissalPath);
     this.canCreateFeedback = data.can_create_feedback || false;
     this.visualReviewAppAvailable = Boolean(data.visual_review_app_available);
-    this.visualReviewFF = gon && gon.features && gon.features.anonymousVisualReviewFeedback;
     this.appUrl = gon && gon.gitlab_url;
 
     this.initCodeclimate(data);