audio policy: add routing update client interface

Added IAudioPolicyServiceClient client binder interface
for client process to receive notifications from AudioPolicyService
when audio ports are added/removed or audio patches created/released.

The audio patches owned by a given client are automatically released when
this client binder dies.

Bug: 14815883.

Change-Id: I6013f6aec03b50565cffb1ad2cd1f0f8852032c5
diff --git a/media/libmedia/Android.mk b/media/libmedia/Android.mk
index f3770e4..69eead3 100644
--- a/media/libmedia/Android.mk
+++ b/media/libmedia/Android.mk
@@ -44,6 +44,7 @@
     JetPlayer.cpp \
     IOMX.cpp \
     IAudioPolicyService.cpp \
+    IAudioPolicyServiceClient.cpp \
     MediaScanner.cpp \
     MediaScannerClient.cpp \
     CharacterEncodingDetector.cpp \