device/sample: Enhanced example to include usage of exposing APIs

Change-Id: Id0c0b2201ecb3d087ec1ae48b6629ee4f403dbfb
diff --git a/products/addon_stub_defs b/products/addon_stub_defs
new file mode 100644
index 0000000..2fed57a
--- /dev/null
+++ b/products/addon_stub_defs
@@ -0,0 +1 @@
++com.example.android.platform_library.*