Update os-attach-interfaces to os-interface

In api doc, the net interface is "os-attach-interfaces",
but the api interface "os-interface" is the actual interface.
so we should correct the doc.

Change-Id: I7007213f9bd61c9ec2427a76c0367d23fb84ec05
Closes-Bug: #1282535
Merge "Update os-attach-interfaces to os-interface"