[Backport] For index routes, sitemap in development project incorrectly shows 'index' instead of folder name

After configuring index routes as mentioned in the documentation , the sitemap in Experience Manager for the development project incorrectly shows as "index" instead of the folder name. This appears to happen only at depth 1. At level 2, the sitemap item does show the correct folder name.

For example, after creating a folder "promotions" & a document in the core named "index" (as mentioned in the 'Create Folders and Index Documents' section of the documentation ), the sitemap shows as 'index' instead of 'promotions'. 

This seems to be a UI bug that was introduced since the documentation was written.