At this time, the 'import subnets' feature of the foreman only import network address and netmask from the DHCP smart-proxy.

This patch will provide the ability to import the following informations from the subnets (if configured for the current subnet on the DHCP server):

• Gateway
• Primary DNS server
• Secondary DNS server
• DHCP range (from IP addr...to IP addr)

This issue is related to the #12211 (smart-proxy implementation that provide the new informations from subnets)