More demo app unstable API opt-in and reshuffling

Follow-up to <unknown commit>

PiperOrigin-RevId: 437777871

demos/main/src/main/java/com/google/android/exoplayer2/demo/PlayerActivity.java

@@ -509,10 +509,15 @@ public class PlayerActivity extends AppCompatActivity
   private static List<MediaItem> createMediaItems(Intent intent, DownloadTracker downloadTracker) {
     List<MediaItem> mediaItems = new ArrayList<>();
     for (MediaItem item : IntentUtil.createMediaItemsFromIntent(intent)) {
-      @Nullable
-      DownloadRequest downloadRequest =
-          downloadTracker.getDownloadRequest(item.localConfiguration.uri);
-      if (downloadRequest != null) {
+      mediaItems.add(
+          maybeSetDownloadProperties(
+              item, downloadTracker.getDownloadRequest(item.localConfiguration.uri)));
+    }
+    return mediaItems;
+  }
+
+  private static MediaItem maybeSetDownloadProperties(
+      MediaItem item, @Nullable DownloadRequest downloadRequest) {
     MediaItem.Builder builder = item.buildUpon();
     builder
         .setMediaId(downloadRequest.id)
@@ -526,12 +531,6 @@ public class PlayerActivity extends AppCompatActivity
       builder.setDrmConfiguration(
           drmConfiguration.buildUpon().setKeySetId(downloadRequest.keySetId).build());
     }
-
-        mediaItems.add(builder.build());
-      } else {
-        mediaItems.add(item);
-      }
-    }
-    return mediaItems;
+    return builder.build();
   }
 }