Adding write permissions to traceur

Fixing denials that stopped traceur from being able to write to
debugfs_tracing. Also cleaning up general find denials for services that
traceur doesn't have permission to access.

Additionally, labeling /data/local/trace as a trace_data_file in order
to give traceur a UX friendly area to write its traces to now that it
will no longer be a shell user. It will be write/readable by traceur,
and deletable/readable by shell.

Test: Traceur functionality is not being blocked by selinux policy
Bug: 68126425
Change-Id: I201c82975a31094102e90bc81454d3c2a48fae36