Build its-base plugin against 3.3

Change-Id: Idbde8c6be3480952780f2a10cbb5692d8962f021
diff --git a/jenkins/gerrit-bazel-plugin-its-base.yaml b/jenkins/gerrit-bazel-plugin-its-base.yaml
index 6e05fd9..4360dd63 100644
--- a/jenkins/gerrit-bazel-plugin-its-base.yaml
+++ b/jenkins/gerrit-bazel-plugin-its-base.yaml
@@ -1,9 +1,15 @@
 - project:
     name: its-base
     jobs:
-      - 'plugin-{name}-bazel-{branch}':
+      - 'plugin-{name}-bazel-{branch}-{gerrit-branch}':
           branch:
             - master
+          gerrit-branch:
+            - master
+            - stable-3.3
+          targets: 'plugins/its-base:its-base plugins/its-base:its_base_tests'
+      - 'plugin-{name}-bazel-{branch}':
+          branch:
             - stable-3.2
             - stable-3.1
             - stable-2.16