fix(ngRequired): change test case to exptect invalid form incase invalid option (required = true)

Author: m-amr

test/ng/directive/ngOptionsSpec.js

@@ -2532,8 +2532,8 @@ describe('ngOptions', function() {
       expect(scope.value).toBe(false);
 
       scope.$apply('required = true');
-      expect(element).toBeValid();
-      expect(scope.value).toBe(false);
+      expect(element).toBeInvalid();
+      expect(scope.value).toBe(undefined);
     });
   });