API to get the IP address of the connected client

The changes are,
1. In case of EAPOL IP address allocation, get the
IP of the connected client from supplicant HAL
AP-STA-CONNECTED event and save it in WifiP2pDevice.
2. Register for onClientsChanged callback function in
TetheringEventCallback interface.
3. Once DHCP server assigns the IP address, the Tethering Manager
calls the onClientsChanged callback function with the IP address
details. Save the IP address in WifiP2pDevice.
4. Send WIFI_P2P_CONNECTION_CHANGED_ACTION broadcast intent
to inform that the IP address is assigned.

Bug: 291202830
Test: Manual - Enabled EAPOL IP address via overlay config file
      and established P2P connection and confirmed from the logs that
      the IP address is set in the WifiP2pDevice.
Test: manual - Establish negotiated P2P connection and confirmed
      from the logs that the IP address is set in the WifiP2pDevice.
Change-Id: I5d5b72e339029810ec8e219c08742c65a526f24d
11 files changed