Add getAvoidBadWifi system API

This helps remove the dependency on MultinetworkPolicyTracker from
IpClient.

Test: atest FrameworksNetTests NetworkStackTests
Bug: 112869080
Change-Id: If56791dbed564772f25a859f301b8b52d84e38a3
diff --git a/core/java/android/net/IConnectivityManager.aidl b/core/java/android/net/IConnectivityManager.aidl
index 3d34574..131925e 100644
--- a/core/java/android/net/IConnectivityManager.aidl
+++ b/core/java/android/net/IConnectivityManager.aidl
@@ -165,6 +165,7 @@
     void setAvoidUnvalidated(in Network network);
     void startCaptivePortalApp(in Network network);
 
+    boolean getAvoidBadWifi();
     int getMultipathPreference(in Network Network);
 
     NetworkRequest getDefaultRequest();