[NETD-BPF#14] Move BPF map definition and utils to frameworks/libs/net/ am: b1d4888ec2 am: 18af063372

Original change: https://android-review.googlesource.com/c/platform/system/bpf/+/1869329

Change-Id: I64f1bd06f39157921b3fee08e18ed65eb770e65f