fix testVerifyOverlay not match multi dtbo_idx in bootconfig am: 24b1fa52de

Original change: https://android-review.googlesource.com/c/platform/test/vts/+/2267671

Change-Id: I6d392edeaa3e22a8867e81c21ee1d0eb417af42f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>