Merge "aconfig: add top level flag read lib api" into main am: e7fde3a8

Original change: https://android-review.googlesource.com/c/platform/build/+/2941627



Change-Id: Ifa7578b3f4e26750c0eeb9b56f665b77cd84b385
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>