Support callback for rpc server

In case that a user want to be notified, a callback will be called after
setting up the RPC server.

Bug: 195381416
Test: atest MicrodroidHostTestCases
Test: run microdroid demo app
Change-Id: Ia98bfb879a434935d9708a6dcd4aa19c4d46ffe4
diff --git a/libs/binder/libbinder_rpc_unstable.map.txt b/libs/binder/libbinder_rpc_unstable.map.txt
index 1138786..e856569 100644
--- a/libs/binder/libbinder_rpc_unstable.map.txt
+++ b/libs/binder/libbinder_rpc_unstable.map.txt
@@ -1,6 +1,7 @@
 LIBBINDER_RPC_UNSTABLE_SHIM { # platform-only
   global:
     RunRpcServer;
+    RunRpcServerCallback;
     RpcClient;
     RpcPreconnectedClient;
   local: