Move TapPacketReader into EthernetTestInterface am: d0d2cb32a9 am: 00b50801b3

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/3189183

Change-Id: Icfff1c5d31f36ad981901141d4469f4fb69410d9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>