Summary: This diff adds a static function `onRegisterDevice` which is being called whenever an device gets registered. This callback is used to add loglisterner for android. I even moved the logic of iOS from `onRegisterPlugin` to this callback. The reason for not adding android log listener in `onRegisterPlugin` was that there were cases when baseDevice was not yet registered before calling `onRegisterPlugin`. For android, I want the instance of `BaseDevice` so that I can add logListener on it.
Reviewed By: danielbuechele
Differential Revision: D13563282
fbshipit-source-id: b5be40f3dbc808bdaeabae28423c563cf2345a22