minor: disable stats job when app is closed

Adds a slight battery performance improvement

#437

app/src/main/java/com/zaneschepke/wireguardautotunnel/service/tunnel/WireGuardTunnel.kt

@@ -273,7 +273,7 @@ constructor(
 	}
 
 	companion object {
-		const val STATS_START_DELAY = 5_000L
+		const val STATS_START_DELAY = 1_000L
 		const val VPN_STATISTIC_CHECK_INTERVAL = 1_000L
 		const val VPN_RESTART_DELAY = 1_000L
 	}

app/src/main/java/com/zaneschepke/wireguardautotunnel/ui/AppViewModel.kt

@@ -94,6 +94,7 @@ constructor(
 	}
 
 	private suspend fun initTunnel() {
+		if (tunnelService.get().getState() == TunnelState.UP) tunnelService.get().startStatsJob()
 		val activeTunnels = appDataRepository.tunnels.getActive()
 		if (activeTunnels.isNotEmpty() &&
 			tunnelService.get().getState() == TunnelState.DOWN

app/src/main/java/com/zaneschepke/wireguardautotunnel/ui/MainActivity.kt

@@ -215,4 +215,9 @@ class MainActivity : AppCompatActivity() {
 			}
 		}
 	}
+	override fun onDestroy() {
+		super.onDestroy()
+		// save battery by not polling stats while app is closed
+		tunnelService.cancelStatsJob()
+	}
 }