DS-4107 Update tests and mocks for metadata as map

src/app/shared/object-grid/collection-grid-element/collection-grid-element.component.spec.ts

@@ -8,21 +8,25 @@ let collectionGridElementComponent: CollectionGridElementComponent;
 let fixture: ComponentFixture<CollectionGridElementComponent>;
 
 const mockCollectionWithAbstract: Collection = Object.assign(new Collection(), {
-  metadata: [
-    {
-      key: 'dc.description.abstract',
-      language: 'en_US',
-      value: 'Short description'
-    }]
+  metadata: {
+    'dc.description.abstract': [
+      {
+        language: 'en_US',
+        value: 'Short description'
+      }
+    ]
+  }
 });
 
 const mockCollectionWithoutAbstract: Collection = Object.assign(new Collection(), {
-  metadata: [
-    {
-      key: 'dc.title',
-      language: 'en_US',
-      value: 'Test title'
-    }]
+  metadata: {
+    'dc.title': [
+      {
+        language: 'en_US',
+        value: 'Test title'
+      }
+    ]
+  }
 });
 
 describe('CollectionGridElementComponent', () => {