Plot of predictions with test data in Colab notebook doesn't make much sense

In the Colab notebook, after the training we plot some graphs.
The last one, which is "Plot the predictions along with to the test data", is literally taken from a standard TensorFlow Lite example notebook (see https://colab.research.google.com/github/tensorflow/tensorflow/blob/master/tensorflow/lite/experimental/micro/examples/hello_world/create_sine_model.ipynb#scrollTo=L_vE-ZDkHVxe )
but does not make much sense in this context.

Besides that, the code for that plot currently (ab)uses a deprecated matplotlib behaviour
```
/usr/local/lib/python3.6/dist-packages/matplotlib/axes/_base.py:380: MatplotlibDeprecationWarning:
cycling among columns of inputs with non-matching shapes is deprecated.
```
which also suggests that the current plot is a bit nonsensical.

Open the Colab notebook and inspect the final "Plot the predictions along with to the test data" section, comparing it with the linked TensorFlow Lite example. Run the notebook through training and revise the plot so it represents the test data and predictions meaningfully without the reported Matplotlib deprecation warning.

Written by the indexing model from the issue text.