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/include/media/AudioSystem.h b/include/media/AudioSystem.h
index 9ea18de..2e3cab0 100644
--- a/include/media/AudioSystem.h
+++ b/include/media/AudioSystem.h
@@ -139,12 +139,12 @@
     // return the number of input frames lost by HAL implementation, or 0 if the handle is invalid
     static uint32_t getInputFramesLost(audio_io_handle_t ioHandle);
 
-    // Allocate a new audio session ID and return that new ID.
-    // If unable to contact AudioFlinger, returns AUDIO_SESSION_ALLOCATE instead.
-    // FIXME If AudioFlinger were to ever exhaust the session ID namespace,
-    //       this method could fail by returning either AUDIO_SESSION_ALLOCATE
-    //       or an unspecified existing session ID.
-    static int newAudioSessionId();
+    // Allocate a new unique ID for use as an audio session ID or I/O handle.
+    // If unable to contact AudioFlinger, returns AUDIO_UNIQUE_ID_ALLOCATE instead.
+    // FIXME If AudioFlinger were to ever exhaust the unique ID namespace,
+    //       this method could fail by returning either AUDIO_UNIQUE_ID_ALLOCATE
+    //       or an unspecified existing unique ID.
+    static audio_unique_id_t newAudioUniqueId();
 
     static void acquireAudioSessionId(int audioSession, pid_t pid);
     static void releaseAudioSessionId(int audioSession, pid_t pid);