Only add the gr-app.js script at the end of the dom

https://github.com/PolymerLabs/crisper

Bug: Issue 12067
Change-Id: Ic01bee6ed87219dc5b9a9d86246b260baeb661da
diff --git a/tools/bzl/js.bzl b/tools/bzl/js.bzl
index 66be264..3208e69 100644
--- a/tools/bzl/js.bzl
+++ b/tools/bzl/js.bzl
@@ -363,6 +363,7 @@
             "python",
             ctx.file._run_npm.path,
             ctx.file._crisper_archive.path,
+            "--script-in-head=false",
             "--always-write-script",
             "--source",
             bundled.path,