Merge "aconfig: create flag value file" into main am: 12eacc1e

Original change: https://android-review.googlesource.com/c/platform/build/+/2901788



Change-Id: I41eb7b32c3a15ed67a1c6d921c153a7fc576a140
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>