Build automerger plugin on stable-3.6

Change-Id: Ief5965a505221cb5babfca910cce30c1303458fe

jenkins/gerrit-bazel-plugin-automerger.yaml

diff --git a/jenkins/gerrit-bazel-plugin-automerger.yaml b/jenkins/gerrit-bazel-plugin-automerger.yaml
index 4b1a4fa..ea3faa5 100644
--- a/jenkins/gerrit-bazel-plugin-automerger.yaml
+++ b/jenkins/gerrit-bazel-plugin-automerger.yaml
@@ -7,7 +7,7 @@
           gerrit-branch:
             - master
             - stable-3.7
-            - stable-3.6
       - 'plugin-{name}-bazel-{branch}':
           branch:
             - master
+            - stable-3.6