UDP connection may be closed before it is actually established

[ameshkov]

Look at this log for instance:

06:09:22.986 [Thread-2511] DEBUG c.a.a.filtering.commons.LogUtils - UDP id=1231 Creating new connection for UDP 172.16.16.1:38042 > 8.8.8.8:53 len=42
06:09:22.986 [Thread-2511] DEBUG c.a.a.filtering.commons.LogUtils - UDP id=1231 Connection has been created.
06:09:22.987 [pool-3-thread-492] DEBUG c.a.a.filtering.commons.LogUtils - UDP id=1231 [OUT] UDP 172.16.16.1:38042 > 8.8.8.8:53 len=42
06:09:22.987 [pool-3-thread-492] DEBUG c.a.a.filtering.commons.LogUtils - UDP id=1231 Open UDP connection to /8.8.8.8:53
06:09:22.987 [pool-4-thread-1] DEBUG c.a.a.filtering.vpn.VpnProxyService - UDP id=1231 Cleaning up connection
06:09:23.029 [Thread-2384] DEBUG c.a.c.io.SocketPollingSelector - UDP id=1231 Read 139 bytes from datagram channel
06:09:23.030 [Thread-2384] DEBUG c.a.a.filtering.commons.LogUtils - UDP id=1231 [IN] UDP 8.8.8.8:53 > 172.16.16.1:38042 len=139

So what happens because of this:

1. Adguard considers this connection as cleaned up and removes it from the list of active connections.
2. In fact it stays alive for all the time.

[ameshkov]

Test build:
https://static.adguard.com/android/release/adguard_issues175.apk

[ameshkov]

Bug is fixed.