Merge "Revert "Reapply "release_config: build flags can be lists""" into main am: cc318d33

Original change: https://android-review.googlesource.com/c/platform/build/+/2818084



Change-Id: Iaee8f8106c5157e9f8f8b3aca8ae6d6bb2c629b5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>