Add NPE check to fix crash in Recents

Bug: 7383315

Author: mikejurka

packages/SystemUI/src/com/android/systemui/recent/RecentTasksLoader.java

@@ -386,7 +386,9 @@ public TaskDescription loadFirstTask() {
             item = createTaskDescription(recentInfo.id,
                     recentInfo.persistentId, recentInfo.baseIntent,
                     recentInfo.origActivity, recentInfo.description);
-            loadThumbnailAndIcon(item);
+            if (item != null) {
+                loadThumbnailAndIcon(item);
+            }
             return item;
         }
         return null;