[FIX] IE9 library CSS not loaded because metadata didn't contain 'name'

The check whether additional CSS files have to be loaded for IE9 
failed because the metadata for the corresponding library did no 
longer contain a 'name' property with the name of the library.

The corresponding check in the ThemeCheck did rely on that property.

Change-Id: I85a881e3aa2369bf432a65b46d4e7da8e35d996b
BCP: 1482021992
CR-Id: 012006153200015210122014