Fix incorrect SELinux labeling.

When moving SELinux rules from file_contexts to genfs_contexts, we
added some genfs rules to label specific files.  It turns out that one
of those files was the prefix of some other files, and since genfs
does prefix-labeling, those other files had their labels changed.

To fix this, we are changing the whole tracefs /instances/wifi from
debugfs_tracing_instances to debugfs_wifi_tracing (a few of the files
already had this label).  This simplifies the rules.

Bug: 62413700
Test: Built, flashed, and booted two devices.  Verified that the files
have the correct context and that wifi, camera, and traceur work.

Change-Id: Id62db079f439ae8c531b44d1184eea26d5b760c3
diff --git a/private/system_server.te b/private/system_server.te
index e06fe4c..f99deb7 100644
--- a/private/system_server.te
+++ b/private/system_server.te
@@ -679,6 +679,7 @@
 
 # Allow WifiService to start, stop, and read wifi-specific trace events.
 allow system_server debugfs_tracing_instances:dir search;
+allow system_server debugfs_wifi_tracing:dir search;
 allow system_server debugfs_wifi_tracing:file rw_file_perms;
 
 # allow system_server to exec shell, asanwrapper & zygote(app_process) on ASAN builds. Needed to run