Use contains_content_type_gated_content attribute, rather than the graded attribute, to determine if the content type gating paywall should be displayed. (#349)

The issue was that items with the graded attribute are not always going to be paywalled by content type gating.
AA-613

src/courseware/data/__factories__/sequenceMetadata.factory.js

@@ -48,6 +48,7 @@ Factory.define('sequenceMetadata')
       complete: unitBlock.complete || null,
       content: '',
       page_title: unitBlock.display_name,
+      contains_content_type_gated_content: unitBlock.contains_content_type_gated_content,
     }),
   ))
   .attrs({

src/courseware/data/api.js

@@ -183,6 +183,7 @@ function normalizeSequenceMetadata(sequence) {
       complete: unit.complete,
       title: unit.page_title,
       contentType: unit.type,
+      containsContentTypeGatedContent: unit.contains_content_type_gated_content,
     })),
   };
 }