@RocketChat/ReactNative

On #987, I fixed a few race conditions, but I left listeners created by RocketChat.subscribeRooms to be closed on the next roomsRequest action.
Although it works in most cases, if the user changes from one server to another, it keeps connect and disconnect listeners opened and it runs roomsRequest before setting next server.

This PR fixes it by moving this.roomsSub back to RocketChat.

Test plan

• Login must request and subscribe to rooms changes
• Changing server must request and subscribe to rooms changes
• With two servers logged in: Logging out from one server must request and subscribe to rooms changes for the other
• Notifications must request and subscribe to rooms changes
• Adding a new server must request and subscribe to rooms changes

Note:

• Request is a /GET Rest API for subscriptions.get and rooms.get
• Subscribe is listening for changes via socket