Switch to cirros uec image in multinode jobs

Kernel panic is seen in these jobs as well,
let's switch to cirros uec image to avoid it.

singlenode jobs already switched with
https://review.opendev.org/q/Ic57f828c08f1793226759baedb3eb2f646191e1f.

Change-Id: I34f3bbf7d30ddce23758ffb513abff0500b1fad6
(cherry picked from commit e04bd8fbdf)
(cherry picked from commit 90a440b081)
Conflicts: zuul.d/tempest-multinode.yaml
(cherry picked from commit b371264f9f)
Conflicts:
	zuul.d/tempest-multinode.yaml

zuul.d/tempest-multinode.yaml

@@ -38,6 +38,10 @@
     voting: false
     vars:
       tox_envlist: integrated-network
+      devstack_localrc:
+        CIRROS_VERSION: 0.5.1
+        DEFAULT_IMAGE_NAME: cirros-0.5.1-x86_64-uec
+        DEFAULT_IMAGE_FILE_NAME: cirros-0.5.1-x86_64-uec.tar.gz
       devstack_services:
         br-ex-tcpdump: true
         br-int-flows: true
@@ -134,6 +138,10 @@
     irrelevant-files: *openvswitch-irrelevant-files
     vars:
       tox_envlist: integrated-network
+      devstack_localrc:
+        CIRROS_VERSION: 0.5.1
+        DEFAULT_IMAGE_NAME: cirros-0.5.1-x86_64-uec
+        DEFAULT_IMAGE_FILE_NAME: cirros-0.5.1-x86_64-uec.tar.gz
       devstack_plugins:
         neutron: https://opendev.org/openstack/neutron.git
       devstack_services:
@@ -170,6 +178,10 @@
     vars:
       devstack_plugins:
         neutron: https://opendev.org/openstack/neutron.git
+      devstack_localrc:
+        CIRROS_VERSION: 0.5.1
+        DEFAULT_IMAGE_NAME: cirros-0.5.1-x86_64-uec
+        DEFAULT_IMAGE_FILE_NAME: cirros-0.5.1-x86_64-uec.tar.gz
       devstack_services:
         br-ex-tcpdump: true
         br-int-flows: true
@@ -247,6 +259,9 @@
             ovn:
               enable_distributed_floating_ip: True
       devstack_localrc:
+        CIRROS_VERSION: 0.5.1
+        DEFAULT_IMAGE_NAME: cirros-0.5.1-x86_64-uec
+        DEFAULT_IMAGE_FILE_NAME: cirros-0.5.1-x86_64-uec.tar.gz
         Q_AGENT: ovn
         ML2_L3_PLUGIN: ovn-router,trunk
         Q_ML2_PLUGIN_MECHANISM_DRIVERS: ovn,logger