bpf: test.c - remove XDP program & add placeholder skfilter program am: 9ba9c1dbb4

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/3256439

Change-Id: If1954e8db3fbc413ce7baf7406e177fe5cfdcc0a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>