Move `runtimeexecutor` to be consumed via prefab

Summary:
This removes the old way of consuming `runtimeexecutor` from
`Android-prebuilt.cmake` to using Prefab which is natively supported
by the Android pipeline.

Changelog:
[Internal] [Changed] - Move `runtimeexecutor` to be consumed via prefab

Reviewed By: cipolleschi

Differential Revision: D39852978

fbshipit-source-id: 87795118f1bcf496a3c50791f920d8b230932555