Run Buildifier as part of the presubmit.

As a result we will catch some errors already in GitHub, and not later in Critique when it's harder to fix them.

PiperOrigin-RevId: 262967050
Change-Id: If598cea7cf9283203bad94533a6bb5be3349e118
diff --git a/.bazelci/presubmit.yml b/.bazelci/presubmit.yml
index f055208..2a35d6d 100644
--- a/.bazelci/presubmit.yml
+++ b/.bazelci/presubmit.yml
@@ -1,4 +1,5 @@
 ---
+buildifier: latest
 platforms:
   ubuntu1604:
     run_targets: