Build stable-3.0 branch of uploadvalidator plugin

Change-Id: I8c7001517b07bb7cafafce93def7b97ee6b67ed6
diff --git a/jenkins/gerrit-bazel-plugin-uploadvalidator.yaml b/jenkins/gerrit-bazel-plugin-uploadvalidator.yaml
index d539b76..3bb4e17 100644
--- a/jenkins/gerrit-bazel-plugin-uploadvalidator.yaml
+++ b/jenkins/gerrit-bazel-plugin-uploadvalidator.yaml
@@ -3,6 +3,7 @@
     jobs:
       - 'plugin-{name}-bazel-{branch}':
           branch:
+            - stable-3.0
             - stable-2.16
       - 'plugin-{name}-bazel-{branch}-{gerrit-branch}':
           branch:
@@ -10,4 +11,3 @@
           gerrit-branch:
             - master
             - stable-3.1
-            - stable-3.0