Domain enabled login screen needs focus on Domain field

After you enable v3 support, you will see a Domain field on
the login screen. However, the focus is still on the Username
field. It should be on the first field which is Domain.

Change-Id: I9d74a4f727d91e0db03988c00e5bc94979966e3b
Closes-bug: #1396812
Merge "Domain enabled login screen needs focus on Domain field"