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