Fix malformed json expectations am: 5bdddf911d

Original change: https://android-review.googlesource.com/c/platform/art/+/2117746

Change-Id: I10c8f4d2009df2d7fc928c082d01b7215a88e4cb
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>