Grant BetterBug access ot WM traces attributes

Currently BetterBug (privileged app) cannot access the details form
/data/misc/wmtrace.

Test: access a trace from /data/misc/wmtrace/ in betterbug
Change-Id: I4cf864ab4729e85f05df8f9e601a75ff8b92bdc8
diff --git a/private/priv_app.te b/private/priv_app.te
index 3ceb7a3..909e676 100644
--- a/private/priv_app.te
+++ b/private/priv_app.te
@@ -79,6 +79,8 @@
 # usual bugreport .zip file). This is used by the bug reporting UI to tell if
 # the bugreport will contain a system trace or not while the bugreport is still
 # in progress.
+allow priv_app wm_trace_data_file:dir r_dir_perms;
+allow priv_app wm_trace_data_file:file getattr;
 allow priv_app perfetto_traces_bugreport_data_file:dir r_dir_perms;
 allow priv_app perfetto_traces_bugreport_data_file:file { getattr };
 # Required to traverse the parent dir (/data/misc/perfetto-traces).