fix(di): allow @Inject(…) to work in dart2js and dynamic reflection

Note: We can’t write a unit test for this as our unit tests
are running in Dartium, where the error does not occur.
However, we previously had a failure in our e2e tests
in `hello_world/index_dynamic.html`
when removing the TODOs in `application.ts`.

Closes #2185

modules/angular2/src/reflection/reflection_capabilities.dart

@@ -57,8 +57,8 @@ class ReflectionCapabilities {
   }
 
   List _convertParameter(ParameterMirror p) {
-    var t = p.type.reflectedType;
-    var res = t == dynamic ? [] : [t];
+    var t = p.type;
+    var res = (!t.hasReflectedType || t.reflectedType == dynamic) ? [] : [t.reflectedType];
     res.addAll(p.metadata.map((m) => m.reflectee));
     return res;
   }