Build checks plugin on stable-3.4 branch

Change-Id: I384ea08ceaf3011fb5212538d5d9010c2383b139
diff --git a/jenkins/gerrit-bazel-plugin-checks.yaml b/jenkins/gerrit-bazel-plugin-checks.yaml
index 8997d0d..57bd028 100644
--- a/jenkins/gerrit-bazel-plugin-checks.yaml
+++ b/jenkins/gerrit-bazel-plugin-checks.yaml
@@ -7,3 +7,8 @@
             - stable-3.3
             - stable-3.2
             - stable-3.1
+      - 'plugin-{name}-bazel-{branch}-{gerrit-branch}':
+          branch:
+            - master
+          gerrit-branch:
+            - stable-3.4