Additionally, add this utility class to IpManager for compatibility
verification. A follow-on CL will make use of IpManager's local
AvoidBadWifiTracker.
Bug: 31827713
Change-Id: If8c56c3f8076d6a5157ea180e361bbdadc2bc1dd
There's a few advantages to having ApfFilter in IpManager:
1. If things go wrong, crashing a particular transport is less bad then
crashing ConnectivityService. We also don't want to use
ConnectivityService as a dumping ground for transport-specific logic.
2. This makes implementing WifiManager.MulticastLock a lot simpler and
safer because enabling/disabling it doesn't have to go through the
NetworkAgent, which could risk various races (e.g. installing a filter
into the wrong WiFi network).
3. IpManager is the ultimate source for LinkProperties for a particular
transport and since ApfFilter uses the LinkProperties it's better to
have it closely paired with the IpManager. Likewise, ApfFilter needs
to know the APF capabilities of the transport, so having it in
the transport avoids having to parcel this information through the
NetworkAgent.
Bug: 26238573
Change-Id: I99b85f2b64972f0e7572170ec5d1926081aa3429
