Build high-availability plugin on stable-2.16

Change-Id: I11e672bd3ffaaf10a2b76bda515b665483d0b264
diff --git a/jenkins/gerrit-buck-bazel-plugin-high-availability.yaml b/jenkins/gerrit-buck-bazel-plugin-high-availability.yaml
index d5d90c9..6bb30d5 100644
--- a/jenkins/gerrit-buck-bazel-plugin-high-availability.yaml
+++ b/jenkins/gerrit-buck-bazel-plugin-high-availability.yaml
@@ -7,6 +7,7 @@
       - 'plugin-{name}-bazel-{branch}':
           branch:
             - master
+            - stable-2.16
             - stable-2.15
             - stable-2.14
       - 'plugin-{name}-gerritforge-{branch}':