Add test for referring to nested types.

Bug: 31821285

Test: `make hidl_test && adb sync && adb shell hidl_test`
Change-Id: Iae030baa5bbe6e890512b494a0b657163c6a99a6

tests/foo/1.0/IFoo.hal

@@ -31,7 +31,7 @@ interface IFoo {
     };
 
     struct Fumble {
-        float x;
+        Outer.Inner data;
     };
 
     typedef Fumble Gumble;

tests/foo/1.0/types.hal

@@ -21,3 +21,13 @@ struct Abc {
     float y;
     handle z;
 };
+
+struct Outer {
+    struct Inner {
+        int32_t data;
+    };
+};
+
+struct Unrelated {
+    Outer.Inner great;
+};