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

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

Change-Id: Ifa3209d08ba059fe5d5b5d8105388593601a5cc3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>