Increase rolling subproces output rollout ratio to 60% am: 7b63baa502

Original change: https://android-review.googlesource.com/c/platform/tools/asuite/+/3379273

Change-Id: I63e866376e5a456a74e1f5bc51820eeb905e7c3b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>