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
diff --git a/private/file_contexts b/private/file_contexts
index 6a94951..2113945 100644
--- a/private/file_contexts
+++ b/private/file_contexts
@@ -350,6 +350,7 @@
 /data/tombstones(/.*)?	u:object_r:tombstone_data_file:s0
 /data/vendor/tombstones/wifi(/.*)? u:object_r:tombstone_wifi_data_file:s0
 /data/local/tmp(/.*)?	u:object_r:shell_data_file:s0
+/data/local/traces(/.*)?	u:object_r:trace_data_file:s0
 /data/media(/.*)?	u:object_r:media_rw_data_file:s0
 /data/mediadrm(/.*)?	u:object_r:media_data_file:s0
 /data/nativetest(/.*)?	u:object_r:nativetest_data_file:s0