Fix long hostname in dnsmasq

dnsmasq only supports 63 character hostnames. Longer names cause
dnsmasq to ignore the entry and not hand out a DHCP address.

Trunacte hostnames longer then 63 characters in order to make
DHCP work.

Closes-Bug: #1238910
Change-Id: Ie1697577bc14038faccd50caf2fea20cac342388
Merge "Fix long hostname in dnsmasq"