Add support for binary flatbuffer config.

Change-Id: I392018952d8cfb1360c9e2c55386718f1b8c4cbc
diff --git a/aos/config.bzl b/aos/config.bzl
index b87fff2..a11efd5 100644
--- a/aos/config.bzl
+++ b/aos/config.bzl
@@ -18,6 +18,7 @@
 def _aos_config_impl(ctx):
     config = ctx.actions.declare_file(ctx.label.name + ".json")
     stripped_config = ctx.actions.declare_file(ctx.label.name + ".stripped.json")
+    binary_config = ctx.actions.declare_file(ctx.label.name + ".bfbs")
 
     flatbuffers_depset = depset(
         ctx.files.flatbuffers,
@@ -31,21 +32,22 @@
 
     all_files = flatbuffers_depset.to_list() + src_depset.to_list()
     ctx.actions.run(
-        outputs = [config, stripped_config],
+        outputs = [config, stripped_config, binary_config],
         inputs = all_files,
         arguments = [
             config.path,
             stripped_config.path,
+            binary_config.path,
             (ctx.label.workspace_root or ".") + "/" + ctx.files.src[0].short_path,
             ctx.bin_dir.path,
         ] + [f.path for f in flatbuffers_depset.to_list()],
         progress_message = "Flattening config",
         executable = ctx.executable._config_flattener,
     )
-    runfiles = ctx.runfiles(files = [config, stripped_config])
+    runfiles = ctx.runfiles(files = [config, stripped_config, binary_config])
     return [
         DefaultInfo(
-            files = depset([config, stripped_config]),
+            files = depset([config, stripped_config, binary_config]),
             runfiles = runfiles,
         ),
         AosConfigInfo(