Skip adding ingress discard rule to legacy VPN am: 5441470a6a

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/28724995

Change-Id: Id1ca486fc765744f96f6ea0f391e6ec4e869a016
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>