Relocate and update desktop-backgrounds-rhel-logos.xml file.
    
    - Previously, wallpaper name was using CentOS Red as first name in the
      list and CentOS Blue farther in the list. Since CentOS default color
      is blue, this layout is not correct. This update changes the
      desktop-backgrounds-rhel-logos.xml file to replace wallpaper name
      from "CentOS Red" to just "CentOS" and from "CentOS Blue" to "CentOS
      Red".
    
    - Previously, desktop-backgrounds-rhel-logos.xml file was stored in
      the root directory. This update creates a desktop-backgrounds
      directory and moves desktop-backgrounds-rhel-logos.xml file into it.