Replace api_files prop to api_contributions am: 25b6cedb25 am: 1e98131d17 am: 0581e4cdb3 am: a14b84920a

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

Change-Id: I592fea86e097f460b882fcfdd0ecdbe60d6664ed
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>