Use provider favicon for preprint discover page (#2032)

app/preprints/discover/route.ts

@@ -3,13 +3,17 @@ import Route from '@ember/routing/route';
 import RouterService from '@ember/routing/router-service';
 import { inject as service } from '@ember/service';
 import config from 'ember-osf-web/config/environment';
+import PreprintProviderModel from 'ember-osf-web/models/preprint-provider';
 
+import MetaTags, { HeadTagDef } from 'ember-osf-web/services/meta-tags';
 import Theme from 'ember-osf-web/services/theme';
 
 export default class PreprintDiscoverRoute extends Route {
     @service store!: Store;
     @service theme!: Theme;
     @service router!: RouterService;
+    @service metaTags!: MetaTags;
+    headTags?: HeadTagDef[];
 
     buildRouteInfoMetadata() {
         return {
@@ -36,6 +40,20 @@ export default class PreprintDiscoverRoute extends Route {
         }
     }
 
+    // TODO: Move this to app/preprints/index/route.ts when landing page PR is merged
+    afterModel(model: PreprintProviderModel) {
+        if (model && model.assets && model.assets.favicon) {
+            const headTags = [{
+                type: 'link',
+                attrs: {
+                    rel: 'icon',
+                    href: model.assets.favicon,
+                },
+            }];
+            this.set('headTags', headTags);
+        }
+    }
+
     deactivate() {
         this.theme.reset();
     }