Build out-of-the-box plugin on stable-3.6

Change-Id: I4480ed21c3bc2acd69b0cb19f707f49054b61be8
diff --git a/jenkins/gerrit-bazel-plugin-out-of-the-box.yaml b/jenkins/gerrit-bazel-plugin-out-of-the-box.yaml
index a7241f1..97693ff 100644
--- a/jenkins/gerrit-bazel-plugin-out-of-the-box.yaml
+++ b/jenkins/gerrit-bazel-plugin-out-of-the-box.yaml
@@ -6,6 +6,7 @@
             - master
           gerrit-branch:
             - master
+            - stable-3.6
             - stable-3.5
             - stable-3.4
             - stable-3.3