This was moved from external/mac-policy.git

ocontexts was split up into 4 files:
1.fs_use
2.genfs_contexts
3.initial_sid_contexts
4.port_contexts

Each file has their respective declerations in them.
Devices, in their respective device directory, can now specify sepolicy.fs_use, sepolicy.genfs_contexts, sepolicy.port_contexts, and sepolicy.initial_sid_contexts. These declerations will be added right behind their respective sepolicy counterparts in the concatenated configuration file.

Signed-off-by: Joshua Brindle <jbrindle@tresys.com>

Change-Id: I22f49db3d59b50ed8975d8c1146bb9c322adbf7e

New property_contexts file for property selabel backend.
New property.te file with property type declarations.
New property_service security class and set permission.
Allow rules for setting properties.

Avoid any future collisions with the use of .fc or .te suffixes in the
per-device directories.  If we want multiple file support, add a separate
subdirectory for sepolicy files.