Rearrange handling of the 'vagrant' user for labs vagrant.

Since we have a 'vagrant' user in ldap, trying to create a local
user causes some conflict.  Just adding the homedir and sudo rule
seems to work fine.

Bug: 63793
Change-Id: I52a207a81119f7e79f65113f272a2b67fe24e0fe
Merge "Rearrange handling of the 'vagrant' user for labs vagrant." into production