Federated learning in android device and use BERT in it

How do we perform inference and train a BERT model on device(android) for Federated Learning
if we use tflite that only performs inference cannot train a .tflite .
And if we use graph tensorflow model ( .pb), android tensorflow says that 1.13.1 version is depricated.
Can you please help in getting BERT model running with Federated learning.