Merge "Build system_ext build.prop with Soong" into main am: 90531960

Original change: https://android-review.googlesource.com/c/platform/build/+/3204711



Change-Id: Ia558f0b18ff172de529c1b772de2db4d07012daf
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>