dscpPolicy: use bpf_net_helpers.h am: 85c9c994ca am: 36598943b7

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/3226109

Change-Id: I44adc72131140372dff3cc40a2c28295b411f3c7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>