Fix json format in expectations file am: 2a89d29a16

Original change: https://android-review.googlesource.com/c/platform/art/+/2111847

Change-Id: I8e869dad316b5860bea3ed478551599186ca27f9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>