libbinder: RPC disambiguate server/client

Now:
- server: RpcServer
- client: a client of an RpcServer
- incoming: a thread processing commands (either as part of an
  RpcServer's sessions or back to a client which has a threadpool)
- outgoing: a thread for sending commands (either to an RpcServer's
  sessions or back to a client which has a threadpool)

Bug: 167966510
Test: binderRpcTest
Change-Id: Iea286ab0ff6f9fb775994247003b8d29c999e10a
diff --git a/libs/binder/RpcState.h b/libs/binder/RpcState.h
index 0dcbb22..d306595 100644
--- a/libs/binder/RpcState.h
+++ b/libs/binder/RpcState.h
@@ -145,9 +145,9 @@
 
     [[nodiscard]] status_t waitForReply(const sp<RpcSession::RpcConnection>& connection,
                                         const sp<RpcSession>& session, Parcel* reply);
-    [[nodiscard]] status_t processServerCommand(const sp<RpcSession::RpcConnection>& connection,
-                                                const sp<RpcSession>& session,
-                                                const RpcWireHeader& command, CommandType type);
+    [[nodiscard]] status_t processCommand(const sp<RpcSession::RpcConnection>& connection,
+                                          const sp<RpcSession>& session,
+                                          const RpcWireHeader& command, CommandType type);
     [[nodiscard]] status_t processTransact(const sp<RpcSession::RpcConnection>& connection,
                                            const sp<RpcSession>& session,
                                            const RpcWireHeader& command);