Add _android files for building DartVM on Android

runtime/bin/dbg_connection_android.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-#ifndef BIN_DBG_CONNECTION_LINUX_H_
-#define BIN_DBG_CONNECTION_LINUX_H_
+#ifndef BIN_DBG_CONNECTION_ANDROID_H_
+#define BIN_DBG_CONNECTION_ANDROID_H_
 
 #include <arpa/inet.h>
 #include <netdb.h>
 #include <sys/socket.h>
 
 
 class DebuggerConnectionImpl {
  public:
   static void StartHandler(int port_number);
 
  private:
   static void SetupPollQueue();
   static void HandleEvent(struct epoll_event* event);
   static void Handler(uword args);
 
   // File descriptors for pipes used to communicate with the debugger thread.
   static int wakeup_fds_[2];
 
   // File descriptor for the polling queue.
   static int epoll_fd_;
 };
 
-#endif  // BIN_DBG_CONNECTION_LINUX_H_
+#endif  // BIN_DBG_CONNECTION_ANDROID_H_