Added empty subscription manager service

Non-functional skeleton. The methods are added because we can't
remove methods in ISub.aidl at this point. Those are still used
by the to-be-removed SubscriptionController.

Bug: 239607619
Test: Manual
Merged-In: I66716314a2e5679e5a4fb7a9e429ae547bd0951d
Change-Id: I66716314a2e5679e5a4fb7a9e429ae547bd0951d
diff --git a/core/res/res/values/config_telephony.xml b/core/res/res/values/config_telephony.xml
index ea2b988..a1d73ff 100644
--- a/core/res/res/values/config_telephony.xml
+++ b/core/res/res/values/config_telephony.xml
@@ -113,4 +113,8 @@
          new network. -->
     <bool name="config_enhanced_iwlan_handover_check">true</bool>
     <java-symbol type="bool" name="config_enhanced_iwlan_handover_check" />
+
+    <!-- Whether using the new SubscriptionManagerService or the old SubscriptionController -->
+    <bool name="config_using_subscription_manager_service">false</bool>
+    <java-symbol type="bool" name="config_using_subscription_manager_service" />
 </resources>