Increase swap size for lvm-barbican jobs

Increase the swap size used by the cinder-tempest-plugin-lvm-barbican
family of jobs by setting it to 8GB in the
cinder-tempest-plugin-lvm-barbican-base-abstract job definition.

Also increase for ctp-lvm-multiattach job, which has been hitting
OOM errors.

See https://review.opendev.org/q/topic:caracal-gate for how we
arrived at 8GB as a suitable value for these jobs.

Change-Id: Id560bc3d078ce2ccbd87b32c317bf61cc519a92a

.zuul.yaml

@@ -72,6 +72,7 @@
       - opendev.org/openstack/cinder-tempest-plugin
       - opendev.org/openstack/cinder
     vars:
+      configure_swap_size: 8192
       tempest_test_regex: '(^tempest\.(api|scenario)|(^cinder_tempest_plugin))'
       tempest_test_exclude_list: '{{ ansible_user_dir }}/{{ zuul.projects["opendev.org/openstack/tempest"].src_dir }}/tools/tempest-integrated-gate-storage-exclude-list.txt'
       # Temporarily exclude TestMultiAttachVolumeSwap until LP bug #1980816 is resolved.
@@ -106,6 +107,7 @@
         devstack_plugins:
           barbican: https://opendev.org/openstack/barbican
     vars:
+      configure_swap_size: 8192
       tempest_test_regex: '(^tempest\.(api|scenario)|(^cinder_tempest_plugin))'
       tox_envlist: all
       devstack_localrc:
@@ -322,7 +324,6 @@
       under FIPS mode
     pre-run: playbooks/enable-fips.yaml
     vars:
-      configure_swap_size: 4096
       nslookup_target: 'opendev.org'
       tempest_exclude_regex: 'test_encrypted_cinder_volumes_cryptsetup'