kleaf: autoload_build_config_constants=if_unset warns. am: 21170ea7fb

Original change: https://android-review.googlesource.com/c/kernel/build/+/3973088

Change-Id: Ia62678b309d8b64205d49d9ff3166f87a71569d6
Signed-off-by: Automerger Merge Worker <[email protected]>