audiopolicy: engineconfigurable: switch to unix socket for PFW debug

SEPolicy rule prevents the audioserver to use tcp / udp sockets.
The Parameter-framework has been updated to use unix socket.
This patch makes use of the unix socket and adds the corresponding
sepolicy rules.

Test: make
Change-Id: I61fcf6fec06a78cf3189c93a86469070ef15bba4
Signed-off-by: François Gaffie <francois.gaffie@renault.com>

media/audioserver/audioserver.rc

@@ -16,3 +16,6 @@ on property:vts.native_server.on=1
     stop audioserver
 on property:vts.native_server.on=0
     start audioserver
+
+on init
+    mkdir /dev/socket/audioserver 0775 audioserver audioserver

services/audiopolicy/engineconfigurable/parameter-framework/examples/ParameterFrameworkConfigurationPolicy.xml.in

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <ParameterFrameworkConfiguration xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    SystemClassName="Policy" ServerPort="5019" TuningAllowed="@TUNING_ALLOWED@">
+    SystemClassName="Policy" ServerPort="/dev/socket/audioserver/policy_debug"
+    TuningAllowed="@TUNING_ALLOWED@">
 
     <SubsystemPlugins>
         <Location Folder="">

services/audiopolicy/engineconfigurable/sepolicy/audioserver.te

@@ -0,0 +1,4 @@
+userdebug_or_eng(`
+  allow audioserver audioserver_socket:dir rw_dir_perms;
+  allow audioserver audioserver_socket:sock_file create_file_perms;
+')

services/audiopolicy/engineconfigurable/sepolicy/file.te

@@ -0,0 +1,2 @@
+# Policy Engine remote connection for runtime debug of parameter framework
+type audioserver_socket, file_type, coredomain_socket;

services/audiopolicy/engineconfigurable/sepolicy/file_contexts

@@ -0,0 +1 @@
+/dev/socket/audioserver(/.*)?    u:object_r:audioserver_socket:s0