Build project-group-structure plugin on stable-3.3 && stable-3.4 branch

Bug: Issue 14304
Change-Id: Ia7c02d517c30285691b2719d2e5c7f5f49a14b3f
diff --git a/jenkins/gerrit-bazel-plugin-project-group-structure.yaml b/jenkins/gerrit-bazel-plugin-project-group-structure.yaml
index 19d302e..064c80e 100644
--- a/jenkins/gerrit-bazel-plugin-project-group-structure.yaml
+++ b/jenkins/gerrit-bazel-plugin-project-group-structure.yaml
@@ -4,6 +4,12 @@
       - 'plugin-{name}-bazel-{branch}':
           branch:
             - master
+            - stable-3.3
             - stable-3.2
             - stable-3.1
             - stable-2.16
+      - 'plugin-{name}-bazel-{branch}-{gerrit-branch}':
+          branch:
+            - master
+          gerrit-branch:
+            - stable-3.4