[automerger skipped] Support chained init_boot partition signing am: acf1b3af -s ours

am skip reason: Merged-In I65fc7913089ae318d90df55a533d3e2ebd93b029 with SHA-1 0d6b727e is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/build/+/20408342



Change-Id: I9701b762e4834b544543a2e06f72f4110a8a9460
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>