Added mock interfaces

Change-Id: I227bb450e714e392a3959c0d314842b9879f8b99
diff --git a/tests/foo/1.0/IFooCallback.hal b/tests/foo/1.0/IFooCallback.hal
new file mode 100644
index 0000000..2bc6c10
--- /dev/null
+++ b/tests/foo/1.0/IFooCallback.hal
@@ -0,0 +1,5 @@
+package android.hardware.tests.foo@1.0;
+
+interface IFooCallback {
+    heyItsMe(IFooCallback cb);
+};