Add extensible choices params

Change-Id: I35ef2f0d9527408be6c419aa4f17cdfc45cf4d73
diff --git a/Dockerfile b/Dockerfile
index d488b08..b06a8ea 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -85,6 +85,7 @@
         discard-old-build \
         docker-workflow \
         extended-choice-parameter \
+        extensible-choice-parameter \
         gerrit-trigger \
         git \
         heavy-job \