Merge "Revert "Revert "Use D8 by default for android_test""" am: 44338663a5

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/2115753

Change-Id: I4e072ffeb5cb68136f8f6bec716fff891af24cf5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>