Enable Blueprint formatting pre-upload check.

Test: Rely on the pre-upload hook.
Bug: 122712425
Change-Id: I45d59d87d9db25f85ceaf0a9f8da71db4fa9774f
diff --git a/PREUPLOAD.cfg b/PREUPLOAD.cfg
new file mode 100644
index 0000000..321bab6
--- /dev/null
+++ b/PREUPLOAD.cfg
@@ -0,0 +1,2 @@
+[Builtin Hooks]
+bpfmt = true