Summary:
There were still some references to "packager/" that are no longer used since the `packager` directory has been deleted after moving to Metro. Cleaned up the ones that were doing nothing and updated the references that are still meaningful.
Closes https://github.com/facebook/react-native/pull/14881

Reviewed By: cpojer

Differential Revision: D5380731

Pulled By: javache

fbshipit-source-id: 1355268f48db47343d0d38fae2598b64c8c01475