Introduce Plugins-stable-3.4 view on Gerrit-CI

Change-Id: I2c2c4062607250f0e5fb71dadc89b0e39e833368
diff --git a/jenkins/gerrit-bazel-plugin-template.yaml b/jenkins/gerrit-bazel-plugin-template.yaml
index 8191a2b..327cc7a 100644
--- a/jenkins/gerrit-bazel-plugin-template.yaml
+++ b/jenkins/gerrit-bazel-plugin-template.yaml
@@ -282,6 +282,7 @@
       - 'Plugins-{branch}'
     branch:
       - master
+      - stable-3.4
       - stable-3.3
       - stable-3.2
       - stable-3.1