Build uploadvalidator plugin on stable-3.3

Change-Id: Ie2988aa883368db9f7dedfa791fdd019da22bbf9
diff --git a/jenkins/gerrit-bazel-plugin-uploadvalidator.yaml b/jenkins/gerrit-bazel-plugin-uploadvalidator.yaml
index 4826ea8..8e5c347 100644
--- a/jenkins/gerrit-bazel-plugin-uploadvalidator.yaml
+++ b/jenkins/gerrit-bazel-plugin-uploadvalidator.yaml
@@ -4,6 +4,7 @@
       - 'plugin-{name}-bazel-{branch}':
           branch:
             - master
+            - stable-3.3
             - stable-3.2
             - stable-3.1
             - stable-3.0