Move *_app into their own file

app.te covers a lot of different apps types (platform_app, media_app,
shared_app, release_app, isolated_app, and untrusted_app), all
of which are going to have slightly different security policies.

Separate the different domains from app.te. Over time, these
files are likely to grow substantially, and mixing different domain types
is a recipe for confusion and mistakes.

No functional change.

Change-Id: Ida4e77fadb510f5993eb2d32f2f7649227edff4f
diff --git a/media_app.te b/media_app.te
new file mode 100644
index 0000000..f0f987f
--- /dev/null
+++ b/media_app.te
@@ -0,0 +1,13 @@
+###
+### Apps signed with the media key.
+###
+
+type media_app, domain;
+permissive media_app;
+app_domain(media_app)
+platform_app_domain(media_app)
+# Access the network.
+net_domain(media_app)
+unconfined_domain(media_app)
+relabelto_domain(media_app)
+allow media_app download_file:dir relabelto;