Fixup test

Author: pranavkm

src/Mvc/test/Mvc.FunctionalTests/InputObjectValidationTests.cs

@@ -261,9 +261,13 @@ public async Task ValidationThrowsError_WhenValidationExceedsMaxValidationDepth(
                 Content = new StringContent(@"{ ""Id"": ""S-1-5-21-1004336348-1177238915-682003330-512"" }", Encoding.UTF8, "application/json"),
             };
 
-            // Act & Assert
-            var ex = await Assert.ThrowsAsync<InvalidOperationException>(() => Client.SendAsync(requestMessage));
-            Assert.Equal(expected, ex.Message);
+            // Act
+            var response = await Client.SendAsync(requestMessage);
+
+            // Assert
+            await response.AssertStatusCodeAsync(HttpStatusCode.InternalServerError);
+            var content = await response.Content.ReadAsStringAsync();
+            Assert.Contains(expected, content);
         }
 
         [Fact]
@@ -356,4 +360,4 @@ public async Task ErrorsDeserializingMalformedXml_AreReportedForModelsWithoutAny
                 });
         }
     }
-}
+}