rename AudioSystem::newAudioSessionId()

Rename AudioSystem::newAudioSessionId() to
AudioSystem::newAudioUniqueId() as it can be used
also for I/O handles.

Bug: 12378680.
Change-Id: I611ea3b5eb57a4b0774437f477ee87dc4ccc2cc2
diff --git a/services/audiopolicy/AudioPolicyClientImpl.cpp b/services/audiopolicy/AudioPolicyClientImpl.cpp
index aa309d1..c0019d1 100644
--- a/services/audiopolicy/AudioPolicyClientImpl.cpp
+++ b/services/audiopolicy/AudioPolicyClientImpl.cpp
@@ -212,4 +212,9 @@
     mAudioPolicyService->onAudioPatchListUpdate();
 }
 
+audio_unique_id_t AudioPolicyService::AudioPolicyClient::newAudioUniqueId()
+{
+    return AudioSystem::newAudioUniqueId();
+}
+
 }; // namespace android