Apply version-script to libaaudio library.

Hides unintentionally exported symbols from the library

Bug: http://b/69603741
Test: make
Change-Id: Ia43ba5b519dc65691d4c010329dee12a3f89ac93
diff --git a/media/libaaudio/Android.bp b/media/libaaudio/Android.bp
index f00f7a8..4857008 100644
--- a/media/libaaudio/Android.bp
+++ b/media/libaaudio/Android.bp
@@ -32,6 +32,7 @@
 cc_library_headers {
     name: "libaaudio_headers",
     export_include_dirs: ["include"],
+    version_script: "libaaudio.map.txt",
 }
 
 subdirs = ["*"]