Add back builds for libaaudio examples

These will actually get installed as tests in /data/nativetest{,64}/...,
instead of into the /system/bin directory.

Test: mmma frameworks/av/media/libaaudio
Change-Id: I41e077e21e3d5c76f0fd5b4f21f7377a0c293740
diff --git a/media/libaaudio/examples/loopback/Android.bp b/media/libaaudio/examples/loopback/Android.bp
new file mode 100644
index 0000000..2b624a8
--- /dev/null
+++ b/media/libaaudio/examples/loopback/Android.bp
@@ -0,0 +1,7 @@
+cc_test {
+    name: "aaudio_loopback",
+    gtest: false,
+    srcs: ["src/loopback.cpp"],
+    shared_libs: ["libaaudio"],
+    header_libs: ["libaaudio_example_utils"],
+}