Provide a way to override the avoid bad wifi configuration

ConnectivityManager.setAvoidUnvalidated only works if the
config_networkAvoidBadWifi configuration is set to 0 and the
NETWORK_AVOID_BAD_WIFI setting is unset. There is no easy way
for a testing app to temporary set a test value to verify the
behavior of the API. Thus, add a mechanism to allow test app
to set a period of time to temporary unstrict the resource
configuration, i.e. Temporary simulate config_networkAvoidBadWifi
configured to 0.

Bug: 186061922
Test: atest CtsNetTestCases FrameworksNetTests
Original-Change: https://android-review.googlesource.com/1733788
Merged-In: If772078c61a9b12926f104d5dfc9c9071e844732
Change-Id: If772078c61a9b12926f104d5dfc9c9071e844732

framework/src/android/net/ConnectivityManager.java

@@ -4721,6 +4721,22 @@ public class ConnectivityManager {
         }
     }
 
+    /**
+     * Temporarily allow bad wifi to override {@code config_networkAvoidBadWifi} configuration.
+     *
+     * @param timeMs The expired current time. The value should be set within a limited time from
+     *               now.
+     *
+     * @hide
+     */
+    public void setTestAllowBadWifiUntil(long timeMs) {
+        try {
+            mService.setTestAllowBadWifiUntil(timeMs);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
     /**
      * Requests that the system open the captive portal app on the specified network.
      *