Fix disableForegroundNdefPush crash.

It crashed due to the fact that we're committing a fragment change
after onSaveInstanceState() is called. Instead, commit without
storing the state - as the NfcFragment is something that needs
to be setup explicitly anyway, it is not something the user
expects to be restored.

Bug: 5540962
Change-Id: I5a8cd0e47306f2bbc14b592a0182083bb79cb21a