Merge "Revert "Reapply "Add support for product-specific build flags""" into...

Merge "Revert "Reapply "Add support for product-specific build flags""" into main am: 5f24ce61 am: 3e228c70 am: 83736642

Original change: https://android-review.googlesource.com/c/platform/build/+/2818085



Change-Id: Ib6026fa5f709502e3599dcc75042647027145ce2
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>