IncFS: update SE policies for the new API

IncFS in S adds a bunch of new ioctls, and requires the users
to read its features in sysfs directory. This change adds
all the features, maps them into the processes that need to
call into them, and allows any incfs user to query the features

Bug: 170231230
Test: incremental unit tests
Change-Id: Ieea6dca38ae9829230bc17d0c73f50c93c407d35
9 files changed