p2p: support factory reset for P2P group

provide system API for Settings

Bug: 109866998
Test: Manual tests
      * manual trigger network reset in below conditions:
        * trigger network reset with P2P on
        * trigger network reset with WiFi on, P2P off
        * trigger network reset with WiFi off
        * trigger network reset with WiFi off then do reboot
      * check groups shown in WiFi Direct page
      * use wpa_cli -i p2p0 list_network
Test: CtsVerifier - WiFi Direct category
Test: Unit tests - atest frameworks/opt/net/wifi/tests/wifitests
Test: Permission check
      * call factoryReset as Guest
      * call factoryReset from 3rd-party application

Change-Id: Id487ebf4564b78b613b550c0f0266effb0ae793e