Add IAudioManager method for releasing a recorder.

oneway releaseRecorder(int riid)
  - unregisters a client recorder

Bug: 123312504
Test: start and stop audio recording, check "dumpsys audio"
Change-Id: I894de434a0bfeaaca37601a406feda1c62e060c7
diff --git a/services/audiomanager/IAudioManager.cpp b/services/audiomanager/IAudioManager.cpp
index f5d4826..6235f06 100644
--- a/services/audiomanager/IAudioManager.cpp
+++ b/services/audiomanager/IAudioManager.cpp
@@ -122,6 +122,13 @@
         data.writeInt32((int32_t) event);
         return remote()->transact(RECORDER_EVENT, data, &reply, IBinder::FLAG_ONEWAY);
     }
+
+    virtual status_t releaseRecorder(audio_unique_id_t riid) {
+        Parcel data, reply;
+        data.writeInterfaceToken(IAudioManager::getInterfaceDescriptor());
+        data.writeInt32((int32_t) riid);
+        return remote()->transact(RELEASE_RECORDER, data, &reply, IBinder::FLAG_ONEWAY);
+    }
 };
 
 IMPLEMENT_META_INTERFACE(AudioManager, "android.media.IAudioService");