Replace api_files prop to api_contributions am: 25b6cedb25 am: 1e98131d17

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2756400

Change-Id: Ib393e5b7721ccc5687e6f8d197c8a02af8b65747
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>