Support multiple Vpn ManageDialogs

Move away from storing the configs in the Intent to prevent issues with
PendingIntents and multiple configs.

The Dialog now queries ConnectivityService for the configuration to
display in the management dialog.

Change-Id: I0e0ef52db840152914d117a24f776d8106e836ff
diff --git a/core/java/android/net/IConnectivityManager.aidl b/core/java/android/net/IConnectivityManager.aidl
index d537b32..0a476eb 100644
--- a/core/java/android/net/IConnectivityManager.aidl
+++ b/core/java/android/net/IConnectivityManager.aidl
@@ -124,6 +124,8 @@
 
     ParcelFileDescriptor establishVpn(in VpnConfig config);
 
+    VpnConfig getVpnConfig();
+
     void startLegacyVpn(in VpnProfile profile);
 
     LegacyVpnInfo getLegacyVpnInfo();