ethernet: fix nullability annotations

Remove a couple of outdated annotations. Both capabilities and IP configuration are guaranteed to be NonNull. There is no need to add a @NonNull annotation as in general, non-nullability is inferred unless marked otherwise.

Change-Id: I75a1d8db23e022134cd805e04e108db3e24d016b
Test: TH
Bug: 257406736
1 file changed