Update openapi to use kube-openapi code

vendor/github.com/coreos/rkt/api/v1alpha/BUILD

@@ -1,5 +1,11 @@
 load("@io_bazel_rules_go//go:def.bzl", "go_library")
 
+filegroup(
+    name = "go_default_library_protos",
+    srcs = ["api.proto"],
+    visibility = ["//visibility:public"],
+)
+
 go_library(
     name = "go_default_library",
     srcs = ["api.pb.go"],
@@ -12,12 +18,6 @@ go_library(
     ],
 )
 
-filegroup(
-    name = "go_default_library_protos",
-    srcs = ["api.proto"],
-    visibility = ["//visibility:public"],
-)
-
 filegroup(
     name = "package-srcs",
     srcs = glob(["**"]),