Summary:
This removes React Transform HMR in favor of the new React Refresh implementation. It should only affect the "Enable Hot Reloading" mode. In further diffs I will remove "React Transform HMR" completely.
This is technically a breaking change for Metro so it'll need a version bump.
Reviewed By: rickhanlonii, rubennorte
Differential Revision: D15903585
fbshipit-source-id: 074380b00868cb31857f599a03799d3584c35d87
Dan Abramov