Build its-base for Gerrit master/stable-2.16

Change-Id: Ia491f3c933c5c8fc3655198bdafe0b7a30edb271
diff --git a/jenkins/gerrit-buck-bazel-plugin-its-base.yaml b/jenkins/gerrit-buck-bazel-plugin-its-base.yaml
index 86b4d29..b9e3385 100644
--- a/jenkins/gerrit-buck-bazel-plugin-its-base.yaml
+++ b/jenkins/gerrit-buck-bazel-plugin-its-base.yaml
@@ -9,7 +9,13 @@
             - stable-2.10
       - 'plugin-{name}-bazel-{branch}':
           branch:
-            - master
             - stable-2.15
             - stable-2.14
           targets: 'plugins/its-base:its-base plugins/its-base:its_base_tests'
+      - 'plugin-{name}-bazel-{branch}-{gerrit-branch}':
+          branch:
+            - master
+          gerrit-branch:
+            - master
+            - stable-2.16
+          targets: 'plugins/its-base:its-base plugins/its-base:its_base_tests'