Merge "Convert firstword/lastword to starlark functions instead of index...

Merge "Convert firstword/lastword to starlark functions instead of index operators" am: 7940585c am: 312fda06

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/2078798



Change-Id: Ib093f7c9aa16e6dc91d62e612944fbbec4839e24
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>