Accept empty labels in hostname for compatibility

RFC1034#section-3.5 doesn't permit empty labels in hostnames, but we
accepted this prior to N and the behavior is used by some apps. We
need to keep the behavior for now for compatibility.

Bug: 25991669
Change-Id: I0c8082572f6bf9ec2dc87aee164aafd6ccdcbfa5
2 files changed