enable ussuri cloud archive on ubuntu bionic

This change updates bionic installs to use the
ussuri cloud archive to enable the use of libvirt 6.0.0.
This is required to prevent a libvirt bug that causes intermittent
failures for the tempest test_live_block_migration_paused testcase.

Change-Id: I9c395c2b5fdfe6ad9a43477280e88e9a9b34f057
Related-Bug: 1901739
diff --git a/tools/fixup_stuff.sh b/tools/fixup_stuff.sh
index c0e07dd..cd7ee59 100755
--- a/tools/fixup_stuff.sh
+++ b/tools/fixup_stuff.sh
@@ -77,10 +77,10 @@
         # If we are on a nodepool provided host and it has told us about
         # where we can find local mirrors then use that mirror.
         source /etc/ci/mirror_info.sh
-        sudo apt-add-repository -y "deb $NODEPOOL_UCA_MIRROR bionic-updates/train main"
+        sudo apt-add-repository -y "deb $NODEPOOL_UCA_MIRROR bionic-updates/ussuri main"
     else
-        # Enable UCA:train for updated versions of QEMU and libvirt
-        sudo add-apt-repository -y cloud-archive:train
+        # Enable UCA:ussuri for updated versions of QEMU and libvirt
+        sudo add-apt-repository -y cloud-archive:ussuri
     fi
     REPOS_UPDATED=False
     apt_get_update