Can't Save after Detach

[mmangliers]

Because we remove the adapter on detach, we can't save after the view is detached (another library I'm using performs the save there, so it's not ideal for me).

A tweak which shouldn't adversely affect anything would be to updateFirstAdapterPosition() in onDetachedFromWindow before removing the adapter, and then we can wrap the call to update in onSaveInstanceState to only occur if the adapter is not null.