Add a key for displaying avoid bad Wi-Fi setting from carrier config

This change introduces a new key in the carrier configuration to decide
if the device's UI should present the "avoid bad Wi-Fi" option.

Flag: android.net.platform.flags.avoid_bad_wifi_from_carrier_config
Bug: 410976315
Test: atest ConnectivityCoverageTests:android.net.connectivity.com.android.server.connectivity.MultinetworkPolicyTrackerTest
Test: atest CtsNetTestCases:android.net.cts.ConnectivityManagerTest
Change-Id: Idcf49509c9e0c6cfc44fc4dc3bf70fe36b3d5309