Expanding a Parent Folder, Opening a Child Folder, and Collapsing the Parent Folder Displays All Assets

In the content browser, expanding a parent folder, selecting one of its child folders, and then collapsing the parent folder will cause all of the assets to display in the content browser, including engine source c++ files.

Found in 4.9.2 binary, 4.8.3 binary, and Main CL 2708796.

1. Open the editor
2. Create a Third Person BP Project W/ Starter Content
3. In the Content Browser, expand the Starter Content Folder
4. Open one of the child folders
5. With that folder still open, collapse the starter content folder.

Result: All of the assets, including C++ source files, will shown in the content browser.

Expected: The Parent folder would collapse and then you would see the folders contained inside of the parent.