Build autosubmitter against gerrit stable-3.6

Bug: Issue 15831
Change-Id: I61566d96980bc573781e8c07a186ef3bd544f294
diff --git a/jenkins/gerrit-bazel-plugin-autosubmitter.yaml b/jenkins/gerrit-bazel-plugin-autosubmitter.yaml
index 47f70c3..bd2aa19 100644
--- a/jenkins/gerrit-bazel-plugin-autosubmitter.yaml
+++ b/jenkins/gerrit-bazel-plugin-autosubmitter.yaml
@@ -6,6 +6,7 @@
             - master
           gerrit-branch:
             - master
+            - stable-3.6
             - stable-3.5
             - stable-3.4
       - 'plugin-{name}-bazel-{branch}':