Remove an old comment that refers to a bug that is fixed am: f250d0b4c0

Original change: https://android-review.googlesource.com/c/platform/art/+/2973516

Change-Id: I1fc35d80738c0d2ab7e17a5683784d7274ad7397
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>