Add support for Nullable IpConfiguration am: 7e81787e0b am: 8900f662e5

Original change: https://android-review.googlesource.com/c/platform/frameworks/opt/net/ethernet/+/2024300

Change-Id: If9f0241c2d725ea2ecaf405cfe81e02f1a0e4e46
tree: ef9eae2ed00f36f2d4641fd5cf2e26494dd5d7fc
  1. java/
  2. tests/
  3. .gitignore
  4. Android.bp
  5. TEST_MAPPING