Summary:
Motivation: perf, simplicity, adhering to new SurfaceMountingManager APIs available to us. Backwards-compatible with events sent through old system or Fabric, to Fabric or non-Fabric Views.
Changelog: [Changed][Android] Old Native method to create ScrollEvent has been deprecated and will be removed at some point in the (distant) future
Reviewed By: mdvacca
Differential Revision: D26027105
fbshipit-source-id: b9dba5b56c2bfed3b8fc4488c54b271b85ab5fa0