Change state of 'lo' interface to 'up' inside net.namespace at creation.

Backported for 4.1.1 from 5.0 (b2bbf0fcadb3b81875ad3aad3971d1b13b57ceac)

Change-Id: Id99dee1e72fccf80be689650fc63cbe9eab06d99
Closes-Bug: #1308356
Merge "Change state of 'lo' interface to 'up' inside net.namespace at creation." into stable/4.1