audio: revert invalid markings

Revert invalid markings added to AOSP files.

CRs-Fixed: 2380934
Change-Id: I5e729616dccb5e04e870e26462f822e16433879d
diff --git a/visualizer/Android.mk b/visualizer/Android.mk
index 3d0f734..f62256b 100644
--- a/visualizer/Android.mk
+++ b/visualizer/Android.mk
@@ -1,4 +1,4 @@
-# Copyright 2013, 2019 The Android Open Source Project
+# Copyright 2013 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.