selinux: New rw privileges for themes

- New theme_data_file context for files under /data/system/theme
- Permit systemserver to create files/dirs under /data/resource-cache
- Permit systemserver to create files/dirs under /data/system/theme

Change-Id: Id597fc20b477ea395a8631623f26a7edde280799
diff --git a/sepolicy/file.te b/sepolicy/file.te
index 3a20199..ddf15b9 100644
--- a/sepolicy/file.te
+++ b/sepolicy/file.te
@@ -2,3 +2,6 @@
 allow file_type rootfs:filesystem associate;
 
 type auditd_log, file_type;
+
+# Themes
++type theme_data_file, file_type, data_file_type;
\ No newline at end of file