ApfFilter: refactor/simplify ipv4 if mMulticastFilter am: 5ecede272b am: 6c6f832fb2

Original change: https://android-review.googlesource.com/c/platform/packages/modules/NetworkStack/+/2857925

Change-Id: I816c5e4f4c1375134ad42cb7d754b391642a5112
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>