Test live migrate on a paused instance

Nova change Ib38eaf412cb51a9cbfc443c5ec15c5797265ddae adds support for
doing live migration of a paused instance, this adds the test to cover
that scenario.

This also depends on a series of devstack-gate changes to support
multi-host testing in the experimental queue. Specifically, this is
tested in the check-tempest-dsvm-aiopcpu-full job.

Depends-On: I89b7e390bf1cf4f2eccabca2e31a9d1b6b270677

Co-Authored By: "Matthew Gilliard <matthew.gilliard@hp.com>"
Related-Bug: #1305062

Change-Id: I5c6fd3de7ea45d1851bb40037c64ad7fb5e6dc48
diff --git a/etc/tempest.conf.sample b/etc/tempest.conf.sample
index 2a72635..6be06b9 100644
--- a/etc/tempest.conf.sample
+++ b/etc/tempest.conf.sample
@@ -396,6 +396,11 @@
 # https://bugs.launchpad.net/nova/+bug/1398999 (boolean value)
 #block_migrate_cinder_iscsi = false
 
+# Does the test system allow live-migration of paused instances? Note,
+# this is more than just the ANDing of paused and live_migrate, but
+# all 3 should be set to True to run those tests (boolean value)
+#live_migrate_paused_instances = false
+
 # Enable VNC console. This configuration value should be same as
 # [nova.vnc]->vnc_enabled in nova.conf (boolean value)
 #vnc_console = false