Upgrade buildifier to 0.22.0

Change-Id: Ib713df603dfdf487bb4e56e20028df75cb3be179
diff --git a/jenkins-docker/slave-bazel-nocache/Makefile b/jenkins-docker/slave-bazel-nocache/Makefile
index e9ba8eb..c80e497 100644
--- a/jenkins-docker/slave-bazel-nocache/Makefile
+++ b/jenkins-docker/slave-bazel-nocache/Makefile
@@ -1,7 +1,7 @@
 NO_CACHE=false
 IMAGE=gerritforge/gerrit-ci-slave-bazel:debian-stretch-nocache
 BAZEL_VER=0.22.0
-BUILDIFIER_VER=0.20.0
+BUILDIFIER_VER=0.22.0
 
 # Targets