Add stable-3.1 branch build for rename-project plugin

Change-Id: I9fc168a716c167a47f733c065f2bb5640b6cb106
diff --git a/jenkins/gerrit-bazel-plugin-rename-project.yaml b/jenkins/gerrit-bazel-plugin-rename-project.yaml
index 61f7c59..39925ae 100644
--- a/jenkins/gerrit-bazel-plugin-rename-project.yaml
+++ b/jenkins/gerrit-bazel-plugin-rename-project.yaml
@@ -4,5 +4,6 @@
       - 'plugin-{name}-bazel-{branch}':
           branch:
             - master
+            - stable-3.1
             - stable-3.0
             - stable-2.16