Angular downgrade memory leak demo

Create memory leak

1. Run npm install for the AngularJS here in the project root folder.
2. Run npm install in the ngx folder.
3. Run npm start in the ngx folder.
4. Open the app in the browser and take a Heap Snapshot (DevTools > Memory). There should be no ContentComponent inside the heap.
5. Click the toggle button 5 times and take a Heap Snapshot. There are 5 instances of ContentComponent in the heap, but should be 1 maximum.