Handle peer-to-peer sync when activity goes to onPause and onResume

[ekigamba]

This issue is supposed to be a discussion on whether the p2p sync is supposed to happen when the activity is no longer visible but not yet exited by the user/app.

This is a case where in android file transfer apps, the user tends to switch applications while the file transfer continues.

In either case, whether the transfer should continue or be paused. I think that it needs to be handled explicitly and documentation from the nearby connections API does not provide as much information as required.