message: Fix two restJson1 error response server protocol tests
  Both these tests assume that error responses in restJson must always be
  indicated with the `X-Amzn-Errortype` header.
diff: @@ -510,8 +510,6 @@ class ServerProtocolTestGenerator(
  FailingTest(RestJson, "RestJsonSupportsNaNFloatQueryValues", Action.Request),
  FailingTest(RestJson, "RestJsonEndpointTrait", Action.Request),
  FailingTest(RestJson, "RestJsonEndpointTraitWithHostLabel", Action.Request),
  - FailingTest(RestJson, "RestJsonInvalidGreetingError", Action.Response),
  - FailingTest(RestJson, "RestJsonComplexErrorWithNoMessage", Action.Response),
  FailingTest(RestJson, "RestJsonFooErrorUsingCode", Action.Response),
  FailingTest(RestJson, "RestJsonFooErrorUsingCodeAndNamespace", Action.Response),
  FailingTest(RestJson, "RestJsonFooErrorUsingCodeUriAndNamespace", Action.Response),
  @@ -652,16 +650,27 @@ class ServerProtocolTestGenerator(
  """.trimMargin()
  ).asObjectNode().get()
  ).build()
  - // This test assumes that errors in responses are identified by an `X-Amzn-Errortype` header with the error shape name.
  + // The following tests assume that errors in responses are identified by an `X-Amzn-Errortype` header with
  + // the error shape name.
  // However, Smithy specifications for AWS protocols that serialize to JSON recommend that new server implementations
  // serialize error types using a `__type` field in the body.
  - // Our implementation follows this recommendation, so we fix the test by removing the header and instead expecting
  + // Our implementation follows this recommendation, so we fix the tests by removing the header and instead expecting
  // the error type to be in the body.
  private fun fixRestJsonEmptyComplexErrorWithNoMessage(testCase: HttpResponseTestCase): HttpResponseTestCase =
  testCase.toBuilder()
  .headers(emptyMap())
  .body("""{"__type":"ComplexError"}""")
  .build()
  + private fun fixRestJsonInvalidGreetingError(testCase: HttpResponseTestCase): HttpResponseTestCase =
  + testCase.toBuilder()
  + .headers(emptyMap())
  + .body("""{"Message":"Hi","__type":"InvalidGreeting"}""")
  + .build()
  + private fun fixRestJsonComplexErrorWithNoMessage(testCase: HttpResponseTestCase): HttpResponseTestCase =
  + testCase.toBuilder()
  + .headers(emptyMap())
  + .body("""{"Nested":{"Fooooo":"bar"},"TopLevel":"Top level","__type":"ComplexError"}""")
  + .build()
  // These are tests whose definitions in the `awslabs/smithy` repository are wrong.
  // This is because they have not been written from a server perspective, and as such the expected `params` field is incomplete.
  @@ -677,6 +686,8 @@ class ServerProtocolTestGenerator(
  private val BrokenResponseTests = mapOf(
  Pair(RestJson, "RestJsonEmptyComplexErrorWithNoMessage") to ::fixRestJsonEmptyComplexErrorWithNoMessage,
  + Pair(RestJson, "RestJsonInvalidGreetingError") to ::fixRestJsonInvalidGreetingError,
  + Pair(RestJson, "RestJsonComplexErrorWithNoMessage") to ::fixRestJsonComplexErrorWithNoMessage,
  )
  }
  }
  