Build healthcheck for Gerrit v3.0

Change-Id: Ie2e5b215ceb9023a35fa9982c8f1069b856a200b
diff --git a/jenkins/gerrit-bazel-plugin-healthcheck.yaml b/jenkins/gerrit-bazel-plugin-healthcheck.yaml
index 2a782ea..6250bd4 100644
--- a/jenkins/gerrit-bazel-plugin-healthcheck.yaml
+++ b/jenkins/gerrit-bazel-plugin-healthcheck.yaml
@@ -4,6 +4,7 @@
       - 'plugin-{name}-bazel-{branch}':
           branch:
             - master
+            - stable-3.0
             - stable-2.16
             - stable-2.15
             - stable-2.14