dscp_policy - use a more efficient v6_equal() am: 3fc472dd39 am: 9208d493c6

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Connectivity/+/2101050

Change-Id: I6c364126d109c80c052876ac2d920cbc665ff566
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>