Fix Settings crash after clicking 'Share Wi-Fi' button

When connecting to an open network, Settings crash after
scanning Wi-Fi DPP QR code and clicking 'Share Wi-Fi' button.

When choosing default network for configurator usage, should
make sure if it supports Wi-Fi DPP or not.

Bug: 126456582
Test: manual test
      atest WifiQrCodeTest
            WifiDppConfiguratorActivityTest
            WifiDppEnrolleeActivityTest
            WifiDppQrCodeGeneratorFragmentTest
            WifiDppQrCodeScannerFragmentTest
            WifiNetworkListFragmentTest
            WifiDppChooseSavedWifiNetworkFragmentTest

Change-Id: I66ee9b01314b84213ecb3016e6e72ff71af8dfc7