Add i777

Change-Id: I63e947f5c63bd2273158c8096df3c4216d4330dc
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