message: change calibrator delegate mechanism to not mark graph immutable.
diff: @@ -33,11 +33,14 @@ TfLiteStatus NodeInfoDelegatePrepare(TfLiteContext* context,
  } // namespace
  TfLiteDelegate CreateNodeInfoDelegate(NodeInfoDelegateParams* params) {
  - return {/*data_ */ params,
  - /* Prepare */ NodeInfoDelegatePrepare,
  - /* CopyFromBufferHandle*/ nullptr,
  - /* CopyToBufferHandle*/ nullptr,
  - /* FreeBufferHandle*/ nullptr};
  + auto delegate = TfLiteDelegateCreate();
  + delegate.data_ = params;
  + delegate.Prepare = NodeInfoDelegatePrepare;
  + delegate.CopyFromBufferHandle = nullptr;
  + delegate.CopyToBufferHandle = nullptr;
  + delegate.FreeBufferHandle = nullptr;
  + delegate.flags = kTfLiteDelegateFlagsAllowDynamicTensors;
  + return delegate;
  }
  TfLiteStatus NodeInfoDelegateObserver::OnDelegatePrepareCalled(
  