Fix TFRemBertEncoder all_hidden_states
# What does this PR do?

Current `TFRemBertEncoder`  adds (initial, after a projection) `hidden_states` twice to `all_hidden_states`.
This PR fixes it.

In the test, it comments `# RemBERT also returns the upprojected word embeddings as an hidden layers`, but the code actually added the projected embedding twice. Furthermore, PyTorch's RemBERT only added the projected one.

@Rocketknight1 @gante 
_The documentation is not available anymore as the PR was closed or merged._<|||||>Applied suggestion

https://github.com/huggingface/transformers/pull/15510#discussion_r799506824
