audio: rename virtualizer stage to spatializer (2)

Update after renaming in system/media includes.

Bug: 188502620
Test: make
Change-Id: I12ed9fbcf2064190d3c59f8003b2d74c07c09a11
diff --git a/services/audioflinger/Threads.h b/services/audioflinger/Threads.h
index 33a83e1..58864e7 100644
--- a/services/audioflinger/Threads.h
+++ b/services/audioflinger/Threads.h
@@ -32,7 +32,7 @@
         OFFLOAD,            // Thread class is OffloadThread
         MMAP_PLAYBACK,      // Thread class for MMAP playback stream
         MMAP_CAPTURE,       // Thread class for MMAP capture stream
-        VIRTUALIZER_STAGE,  //
+        SPATIALIZER,  //
         // If you add any values here, also update ThreadBase::threadTypeToString()
     };
 
@@ -1051,7 +1051,7 @@
                 PlaybackThread::Track* getTrackById_l(audio_port_handle_t trackId);
 
                 bool hasMixer() const {
-                    return mType == MIXER || mType == DUPLICATING || mType == VIRTUALIZER_STAGE;
+                    return mType == MIXER || mType == DUPLICATING || mType == SPATIALIZER;
                 }
 protected:
     // updated by readOutputParameters_l()