[automerger skipped] DscpPolicyTest: use tap instead of tun am: 8a42c7c674 -s ours

am skip reason: skipped by user prohr

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2190935

Change-Id: Ifd2497672a814c19ebb40f45fc972051fe781318
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>