Update simulations python notebook.
Update simulations python notebook.

-   Remove used of deprecated tff.learning.from_compiled_keras_model
-   Remove warning filtering
-   Use kwargs OrderedDict construction
-   batch before mapping in dataset pipeline
-   Stop flattening in Keras model when dataset is already flattening

PiperOrigin-RevId: 295471136

tensorflow/federated,tensorflow/federated,tensorflow/federated