Add disconnect reason to hostapd

Report the reason a client disconnected as part of the
onConnectedClientsChanged callback.

Bug: 361651437
Test: VtsHalHostapdTargetTest
Test: VtsHalWifiSupplicantStaIfaceTargetTest
Test: VtsHalWifiSupplicantStaNetworkTargetTest
Test: VtsHalWifiSupplicantP2pIfaceTargetTest
Change-Id: I93db0f5d379a598d64def9b807c9de666fb3eb0a
12 files changed