Merge "Differentiate between empty and nil input" into udc-dev am: 267a137415 am: 726911e15f

Original change: https://googleplex-android-review.googlesource.com/c/platform/build/soong/+/23374038

Change-Id: I9daafc317680d748dd69d3c60038b89454aea6d7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>