Revert "Support running run-tests under nohup" am: 22503c540f

Original change: https://android-review.googlesource.com/c/platform/art/+/2946645

Change-Id: Iea54a92e2fa2f1080d8a22f984d2e9607222252a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>