Improper include generated when C++ class is in a subdirectory

This is not a regression from 4.27.2, however, a similar issue was fixed in 4.26.

Generating a C++ class that is in a subdirectory generates the #include "Subdirectory/Class.h" instead of #include "Class.h" causing the build to fail.

1. Create or open any C++ project
2. Select Tools > New C++ Class
3. In the wizard select Actor for the parent class then next
4. For the Path select the Folder icon then create a new folder in the director
5. Select the new folder then choose the Select Folder option
6. Select Create Class

Expected Results:
The class is created and the build succeeds

Actual Results:
The class is created with the wrong #include and the build fails