Refactor Drop EtherCat packet test am: 6f6b1a4684 am: 6fe28f1fac

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/3158803

Change-Id: I57c5c1b7dd4cb02ec7d2af9443dab21c24e22b2e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>