Add missing import to fakelibvirt.

This module calls time.sleep(1), but was not importing the time module.
This fixes it.

Fix bug 1133056.

Change-Id: Ifbba2a98ccdd8d5e26ce466831618ccab9e0b462
Merge "Add missing import to fakelibvirt."
Merge remote-tracking branch 'm_src_repo/master' into build-temp