Rename generate-interfaces-file.sh...

Rename generate-interfaces-file.sh to dhcp-all-interfaces.sh
so that it is easier to find/remember in the $PATH on a deployed
image.

Also, on some distros the script actually generates many files
so the previous name was a bit confusing.

Change-Id: I7152fa7c28e8ade251311da2cd5f75972423b66c
Merge "Rename generate-interfaces-file.sh..."