libnetutils/packet.c - fix a raw socket reception race

A socket created bound to a specific protocol can receive packets before
it's bound to a specific interface/mac.

It's best to rely on the bind().

This replicates the way packet sockets are created in external/android-clat.
See: ring.c ring_create() and clatd.c configure_packet_socket()

Test: builds, atest
Bug: 155297277
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I569d2b81a396f352ab5d1b71bd5ad0d96217aab1