Merge "Update retrofit_gki.sh for new init_boot plan" am: ac75382f8b am: 7782ab502d am: dd235e1a8f

Original change: https://android-review.googlesource.com/c/platform/system/tools/mkbootimg/+/1976890

Change-Id: Ib42e52980c76eb229569844174bcf4ac4dafcadf