Attempt cross-SIM enablement when auto data switch enabled

- For devices that have opted in with overlay config, enabling a 2nd SIM
and modifying 'Switch mobile data automatically' will update cross-SIM
calling enablement.
- These updates will be logged as settings events.

Bug: 260266794
Test: Live tests for cross-SIM calling across both subs.
Change-Id: I64d25ca406877ca5f061064e0a3b23f54c125638

src/com/android/settings/network/ProxySubscriptionManager.java

@@ -20,6 +20,7 @@ import static androidx.lifecycle.Lifecycle.Event.ON_DESTROY;
 import static androidx.lifecycle.Lifecycle.Event.ON_START;
 import static androidx.lifecycle.Lifecycle.Event.ON_STOP;
 
+import android.annotation.NonNull;
 import android.content.Context;
 import android.os.Looper;
 import android.provider.Settings;
@@ -241,6 +242,15 @@ public class ProxySubscriptionManager implements LifecycleObserver {
         return mSubscriptionMonitor.getAccessibleSubscriptionInfo(subId);
     }
 
+    /**
+     * Gets a list of active, visible subscription Id(s) of the currently active SIM(s).
+     *
+     * @return the list of subId's that are active and visible; the length may be 0.
+     */
+    public @NonNull int[] getActiveSubscriptionIdList() {
+        return mSubscriptionMonitor.getActiveSubscriptionIdList();
+    }
+
     /**
      * Clear data cached within proxy
      */