Keras-ify NCF TPU embedding lookup (#5641)
Keras-ify NCF TPU embedding lookup (#5641)

* Keras-ify TPU embedding lookup

* delint

* pull get_variable() out of keras lambda

* delint

* move get_variable under variable scope

derekjchow/models,alexgorban/models,cshallue/models,tombstone/models,cshallue/models,cshallue/models,alexgorban/models,tombstone/models,derekjchow/models,tombstone/models,tombstone/models,derekjchow/models,alexgorban/models,cshallue/models,tombstone/models,alexgorban/models,cshallue/models,alexgorban/models,derekjchow/models,tombstone/models,derekjchow/models