Summary:
Rearranges folly_futures configuration into a static library only required for `hermes-inspector` + `folly_runtime` which merges `folly_json` and mutex-related implementations `folly_futures` was used for. As `hermes-executor-debug` is removed by `vmCleanup` configurations later, it allows to shave additional 300KB from the release APK size.
Changelog: [Internal] - Rearrange folly build to reduce APK size
Reviewed By: cortinico
Differential Revision: D34342514
fbshipit-source-id: b646680343e6b9a7674019506b87b96f6007caf2