Merge changes from topic "system_ext_sepolicy"

* changes:
  Separate system_ext_mac_permissions.xml out of system sepolicy.
  Separate system_ext_service_contexts out of system sepolicy.
  Separate system_ext_property_contexts out of system sepolicy.
  Separate system_ext_hwservice_contexts out of system sepolicy.
  Separate system_ext_seapp_contexts out of system sepolicy.
  Separate system_ext_file_contexts out of system sepolicy.
  Separate system_ext_sepolicy.cil out of system sepolicy