Merge "Reland "Mark BOARD_BUILD_SYSTEM_ROOT_IMAGE as KATI_obsolete_var"" am:...

Merge "Reland "Mark BOARD_BUILD_SYSTEM_ROOT_IMAGE as KATI_obsolete_var"" am: ed564963 am: 4d6be0d1

Original change: https://android-review.googlesource.com/c/platform/build/+/2269466



Change-Id: I5c5b644295501bd45220912d0c08b88fa18822c5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>