Merge "aconfig: simplify is_valid_container" into main am: 868f3e8d

Original change: https://android-review.googlesource.com/c/platform/build/+/2900893



Change-Id: I7f61369ccb607e50b58515794f76646c31579fc4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>