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/include/media/IAudioPolicyService.h b/include/media/IAudioPolicyService.h
index 6b6df6e..d422aa3 100644
--- a/include/media/IAudioPolicyService.h
+++ b/include/media/IAudioPolicyService.h
@@ -25,6 +25,7 @@
 #include <utils/Errors.h>
 #include <binder/IInterface.h>
 #include <media/AudioSystem.h>
+#include <media/IAudioPolicyServiceClient.h>
 
 #include <system/audio_policy.h>
 
@@ -124,6 +125,7 @@
     /* Set audio port configuration */
     virtual status_t setAudioPortConfig(const struct audio_port_config *config) = 0;
 
+    virtual void registerClient(const sp<IAudioPolicyServiceClient>& client) = 0;
 };