Read ro.boot.hypervisor.vm_dtbo_idx while writing dtbo am: a0d553b55a

Original change: https://android-review.googlesource.com/c/platform/packages/modules/Virtualization/+/2719235

Change-Id: I5101971e2fcf3e4f6e8f7a6b6767c6c24c3ed61c
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>