Merge "Export build flags to soong." into main am: 2ab031f4 am: 1d6e69cd am: 5ef54931

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/2803674



Change-Id: I52af4213a59f60378f0c1679ae19f00a3dea4c34
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>