sepolicy(wifi): Allow audio service access from wifi

Denial log:
10-03 13:37:05.726   603   603 I auditd  : avc:  denied  { find }
for pid=5443 uid=1073 name=media.audio_policy scontext=u:r:network_stack:s0
`1tcontext=u:object_r:audioserver_service:s0 tclass=service_manager permissive=0

Bug: 142053371
Bug: 135691051
Test: Device boots up and connects to network. No selinux denial seen
from network_stack

Change-Id: I0907504d02c987398467148c26a0847b5f8a7a8c
diff --git a/private/network_stack.te b/private/network_stack.te
index a969986..4fd31bd 100644
--- a/private/network_stack.te
+++ b/private/network_stack.te
@@ -45,6 +45,7 @@
 ')
 
 # Binder IPC.
+allow network_stack audioserver_service:service_manager find;
 allow network_stack network_score_service:service_manager find;
 allow network_stack network_stack_service:service_manager find;
 allow network_stack radio_service:service_manager find;