Merge "Remove deprecated BOARD_BUILD_SYSTEM_ROOT_IMAGE" am: 9b123de886 am: 9055806368

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2239484

Change-Id: Ib339f2f52418f2867d8e1fd6be91c52f0b73d9e4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>