Fix typos in string constants

These were copy/paste errors in code that was copied from AudioTrack.

Change-Id: I64a04d6026667884ddb1fefba67a71d69c691d62
diff --git a/media/libmedia/Visualizer.cpp b/media/libmedia/Visualizer.cpp
index 478654a..13b64e9 100644
--- a/media/libmedia/Visualizer.cpp
+++ b/media/libmedia/Visualizer.cpp
@@ -73,7 +73,7 @@
     if (status == NO_ERROR) {
         if (t != 0) {
             if (enabled) {
-                t->run("AudioTrackThread");
+                t->run("Visualizer");
             } else {
                 t->requestExit();
             }