Fix static flatbuffer rule visibility

We weren't passing through the visibility for the reflection_out alias
that the aos_config rules rely on.

Change-Id: Iedc934dd0da443bb8815a2dd0f448ff3ce8415d7
Signed-off-by: James Kuszmaul <james.kuszmaul@bluerivertech.com>
diff --git a/aos/flatbuffers/generate.bzl b/aos/flatbuffers/generate.bzl
index ad428c3..8fef0ba 100644
--- a/aos/flatbuffers/generate.bzl
+++ b/aos/flatbuffers/generate.bzl
@@ -49,4 +49,5 @@
     native.alias(
         name = name + "_reflection_out",
         actual = name + fbs_suffix + "_reflection_out",
+        visibility = visibility,
     )