Change home directory of vagrant user

The Labsvagrant module tries to create a new directory
at the systems default HOME.
Vagrant uses hard links to /home/vagrant.
This change ensures that the vagrant user home is set to
/home/vagrant.

Bug: 62470
Change-Id: I08b16b7c18a6ebffa551b7f62282378cbd5b79a6
Merge "Change home directory of vagrant user" into production