Improve attempts to re-connect by listening for connectivity changes

When the device loses its internet connection, we do currently queue the messages that cannot be send. The library will then try to re-connect several times. If it fails every time, the library will just stop trying and disconnect. If connection can be re-established, the queued messages are dispatched.

We could enhance the process of trying to re-connect by listening for connectivity changes. This could be more efficient. The required permission `` will not always be there, but when it is, we can use a broadcast receiver for ``.

Start by reviewing the library's reconnect and queued-message flow, then check how Android connectivity changes can be observed when ACCESS_NETWORK_STATE is available. Done means reconnection attempts respond to CONNECTIVITY_CHANGE when permitted, while the existing behavior still works when that permission is absent.

Written by the indexing model from the issue text.