Android: WebSocket closes after short time of inactivity

[CrsiX]

When the screen went off for something like a minute, the WebSocket connection gets closed. Examine ways to keep the connection open as long as possible without forcing the whole app to stay in the foreground.

This is related to #3.

[CrsiX]

In the current test, the WebSocket died after relatively exactly 15 minutes (screen was kept on, app was in the background). The retry-coroutines jumped on board and retried re-connecting the WebSocket, but it failed with ConnectTimeout after exactly 5 seconds, despite WiFi being available. Could the network be throttled?

The attempts to re-connect the WebSocket were going on for around 90 seconds before they stopped, alongside a coroutine which just printed numbers to verify it: the app was suspended by the system.
On re-opening the app, both the onCreate and onResume events got fired, so the app was completely closed, I suspect?

[CrsiX]

Running a "Service" would solve that problem. However, this is currently out of scope, since the base game doesn't provide that functionality either. The current solution is good enough, since it works as long as the game is in the background (paused but not destroyed). The current V2 turn checker also provides relatively good support for re-connects and receiving updates in time.