Build API stubs instead of implementation jars for i18n and Conscrypt am: 80ae94ad4a

Original change: https://android-review.googlesource.com/c/platform/art/+/2102196

Change-Id: I286000800266c86ef302c1a48c58e0f63f7af3c9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>