Summary:
RCTNetworking.startObserving and RCTNetworking.stopObserving don't exist. The main purpose of RCTEventEmitter.addListener is to call these methods, and increment the `_listeners` counter, so that we can start dispatching events when `_listeners > 0`. In D24272560, I made RCTEventEmitter dispatch events even when _listeners <= 0. This is sufficient for us to stop calling these two RCTNetworking methods entirely.
Changelog: [Internal]
Reviewed By: fkgozali
Differential Revision: D24272663
fbshipit-source-id: de9c968bc71e6e6d69a22b934644e6dfa3266b3f