Support bringing up restricted wifi

This CL allows the Carrier Config app to request restricted WiFi nework
by setting the correspoding subscription ID in the network request.

Bug: 315835605
Test: atest android.net.cts.NetworkRequestTest
      atest ConnectivityCoverageTests:android.net.connectivity.com.android.server.connectivity.CarrierPrivilegeAuthenticatorTest
      atest ConnectivityCoverageTests:android.net.connectivity.com.android.server.ConnectivityServiceTest

Change-Id: I237e692d092ff5f969ce4b7962f6d58099a6f3a9
diff --git a/framework/api/current.txt b/framework/api/current.txt
index 554301b..b23bd91 100644
--- a/framework/api/current.txt
+++ b/framework/api/current.txt
@@ -315,6 +315,7 @@
     method @Nullable public android.net.NetworkSpecifier getNetworkSpecifier();
     method public int getOwnerUid();
     method public int getSignalStrength();
+    method @FlaggedApi("com.android.net.flags.request_restricted_wifi") @NonNull public java.util.Set<java.lang.Integer> getSubscriptionIds();
     method @Nullable public android.net.TransportInfo getTransportInfo();
     method public boolean hasCapability(int);
     method public boolean hasEnterpriseId(int);
@@ -419,6 +420,7 @@
     method public int describeContents();
     method @NonNull public int[] getCapabilities();
     method @Nullable public android.net.NetworkSpecifier getNetworkSpecifier();
+    method @FlaggedApi("com.android.net.flags.request_restricted_wifi") @NonNull public java.util.Set<java.lang.Integer> getSubscriptionIds();
     method @NonNull public int[] getTransportTypes();
     method public boolean hasCapability(int);
     method public boolean hasTransport(int);
@@ -438,6 +440,7 @@
     method @NonNull public android.net.NetworkRequest.Builder setIncludeOtherUidNetworks(boolean);
     method @Deprecated public android.net.NetworkRequest.Builder setNetworkSpecifier(String);
     method public android.net.NetworkRequest.Builder setNetworkSpecifier(android.net.NetworkSpecifier);
+    method @FlaggedApi("com.android.net.flags.request_restricted_wifi") @NonNull public android.net.NetworkRequest.Builder setSubscriptionIds(@NonNull java.util.Set<java.lang.Integer>);
   }
 
   public class ParseException extends java.lang.RuntimeException {