Merge "Disallow missing api source files for java_api_library module" am:...

Merge "Disallow missing api source files for java_api_library module" am: 0393174f am: 8faf87a3 am: 3a910094

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/2593068



Change-Id: I883e7d22cf1d1ce48400b6627539aaf711cf4329
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>