Extend access to proc/asound/*

Renamed this type:
proc_asound_cards -> proc_asound

Labeled /proc/asound/devices as proc_asound.

We now use proc_asound type to label files under /proc/asound which we
want to expose to system components.

Bug: 66988327
Test: Pixel 2 boots, can play sound with or without headphones, and
selinux denials to proc_asound are not seen.

Change-Id: I453d9bfdd70eb80931ec9e80f17c8fd0629db3d0
diff --git a/private/system_server.te b/private/system_server.te
index c1b184a..8f9091d 100644
--- a/private/system_server.te
+++ b/private/system_server.te
@@ -675,7 +675,7 @@
 r_dir_file(system_server, cgroup)
 allow system_server ion_device:chr_file r_file_perms;
 
-r_dir_file(system_server, proc_asound_cards)
+r_dir_file(system_server, proc_asound)
 r_dir_file(system_server, proc_loadavg)
 r_dir_file(system_server, proc_meminfo)
 r_dir_file(system_server, proc_net)