Add the netfilter generic message header to
the netlink req. This is needed so the kernel
won't ignore the request for invalid params.
Bug: 149109043
Test: ConntrackSocketTest
Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1424920/
Merged-In: I3f1d7019f1a12647b78630a412df3adf03e9e95a
Change-Id: I63ca166851d6ca2c4737b263dde14c8d794a7d10