Updated name from lstm_prediction.py_tf to lstm_prediction.py and also imported keras (#4422)

* Updated name from lstm_prediction.py_lf to lstm_prediction.py and also imported keras

* Edited the changes

* tensorflow 2.5 is has shipped!!!

* Update lstm_prediction.py

* Update lstm_prediction.py

* One blank line, not two?

Co-authored-by: Christian Clauss <cclauss@me.com>