Perfetto SELinux policies

Perfetto is a performance instrumentation and logging framework,
living in AOSP's /external/pefetto.
Perfetto introduces in the system one binary and two daemons
(the binary can specialize in either depending on the cmdline).

1) traced: unprivileged daemon. This is architecturally similar to logd.
   It exposes two UNIX sockets:
   - /dev/socket/traced_producer : world-accessible, allows to stream
     tracing data. A tmpfs file descriptor is sent via SCM_RIGHTS
     from traced to each client process, which needs to be able to
     mmap it R/W (but not X)
   - /dev/socket/traced_consumer : privilege-accessible (only from:
     shell, statsd). It allows to configure tracing and read the trace
     buffer.
2) traced_probes: privileged daemon. This needs to:
   - access tracingfs (/d/tracing) to turn tracing on and off.
   - exec atrace
   - connect to traced_producer to stream data to traced.

init.rc file:
https://android-review.googlesource.com/c/platform/external/perfetto/+/575382/14/perfetto.rc

Bug: 70942310
Change-Id: Ia3b5fdacbd5a8e6e23b82f1d6fabfa07e4abc405
diff --git a/private/file_contexts b/private/file_contexts
index 0765ef0..de959d4 100644
--- a/private/file_contexts
+++ b/private/file_contexts
@@ -146,6 +146,8 @@
 /dev/socket/tombstoned_crash u:object_r:tombstoned_crash_socket:s0
 /dev/socket/tombstoned_java_trace u:object_r:tombstoned_java_trace_socket:s0
 /dev/socket/tombstoned_intercept u:object_r:tombstoned_intercept_socket:s0
+/dev/socket/traced_producer	u:object_r:traced_producer_socket:s0
+/dev/socket/traced_consumer	u:object_r:traced_consumer_socket:s0
 /dev/socket/uncrypt	u:object_r:uncrypt_socket:s0
 /dev/socket/vold	u:object_r:vold_socket:s0
 /dev/socket/webview_zygote	u:object_r:webview_zygote_socket:s0
@@ -240,6 +242,8 @@
 /system/bin/lmkd        u:object_r:lmkd_exec:s0
 /system/bin/inputflinger u:object_r:inputflinger_exec:s0
 /system/bin/logd        u:object_r:logd_exec:s0
+/system/bin/traced        u:object_r:traced_exec:s0
+/system/bin/traced_probes        u:object_r:traced_probes_exec:s0
 /system/bin/uncrypt     u:object_r:uncrypt_exec:s0
 /system/bin/update_verifier u:object_r:update_verifier_exec:s0
 /system/bin/logwrapper  u:object_r:system_file:s0