atrace and its atrace_exec now exist only in private policy.

Test: No change to policy according to sesearch, except for
      disappearance of all allow rules to do with atrace_current
      which is expected now that atrace cannot be referenced from
      public or vendor policy.
Bug: 31364497

Change-Id: Ib726bcf73073083420c7c065cbd39dcddd7cabe3

Because I'm nitpicky.

Test: policy compiles
Change-Id: I4d886d0d6182d29d7b260cf1f142c47cd32eda29

Make all platform tyeps public to start to prevent build breakage in any devices
that may have device-specific policy using these types.  Future changes will
need to be carefully made to ensure we properly limit types for use by
non-platform policy.

Test: Builds
Change-Id: I7349940d5b5a57357bc7c16f66925dee1d030eb6

Divide policy into public and private components.  This is the first
step in splitting the policy creation for platform and non-platform
policies.  The policy in the public directory will be exported for use
in non-platform policy creation.  Backwards compatibility with it will
be achieved by converting the exported policy into attribute-based
policy when included as part of the non-platform policy and a mapping
file will be maintained to be included with the platform policy that
maps exported attributes of previous versions to the current platform
version.

Eventually we would like to create a clear interface between the
platform and non-platform device components so that the exported policy,
and the need for attributes is minimal.  For now, almost all types and
avrules are left in public.

Test: Tested by building policy and running on device.

Change-Id: Idef796c9ec169259787c3f9d8f423edf4ce27f8c

The label for /sys/kernel/debug/tracing was changed from debugfs
to debugfs_tracing in commit https://android-review.googlesource.com/187692 .
Ensure we're using the correct label.

Change-Id: I6cab9d6b9f3d96b41db26642b67d880b1ca17a8b

Motivation: Domain is overly permissive. Start removing permissions
from domain and assign them to the domain_deprecated attribute.
Domain_deprecated and domain can initially be assigned to all
domains. The goal is to not assign domain_deprecated to new domains
and to start removing domain_deprecated where it is not required or
reassigning the appropriate permissions to the inheriting domain
when necessary.

Bug: 25433265
Change-Id: I8b11cb137df7bdd382629c98d916a73fe276413c

This CL adds the SELinux settings required to support tracing
during boot.
https://android-review.googlesource.com/#/c/157163/

BUG: 21739901
Change-Id: Ib3a7107776141ac8cf4f1ca06674f47a0d4b6ae0