Add test for referring to nested types.

Bug: 31821285

Test: `make hidl_test && adb sync && adb shell hidl_test`
Change-Id: Iae030baa5bbe6e890512b494a0b657163c6a99a6
diff --git a/tests/foo/1.0/IFoo.hal b/tests/foo/1.0/IFoo.hal
index d0119ec..5cbacd2 100644
--- a/tests/foo/1.0/IFoo.hal
+++ b/tests/foo/1.0/IFoo.hal
@@ -31,7 +31,7 @@
     };
 
     struct Fumble {
-        float x;
+        Outer.Inner data;
     };
 
     typedef Fumble Gumble;