Move Session2Token to media apex

Test: build
Change-Id: Id55fe0fa8596f98a84f5bdc89755631b18c7d308
diff --git a/media/Android.bp b/media/Android.bp
index 1c9a7f0..1aefebe 100644
--- a/media/Android.bp
+++ b/media/Android.bp
@@ -62,6 +62,7 @@
         "apex/java/android/media/Session2Command.java",
         "apex/java/android/media/Session2CommandGroup.java",
         "apex/java/android/media/Session2Link.java",
+        "apex/java/android/media/Session2Token.java",
     ],
 }