Add netlinkSocketForProto() without buffersize. am: 1d8b7cc422 am: 56669bf636

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2942526

Change-Id: I79c9c6b95265ab7b684d9ca1f1e35e5b6107f53e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>