Merge "Make system partition import system_ext's aconfig flags" into main am: 8d3ab2d0e8

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/3413680

Change-Id: I3d3992759babe196211673bfa43c7bf04df63698
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>