Modify to limit the size of message for socket ipc

Modify to limit the size of message for socket ipc

[Problem]
  DoS is available by calling g_malloc0 with too big msg_size value.

[Solution]
  The size of messages with socket has been limited to 10kbytes and
  large messages will be sent as file.

Change-Id: Ie2cf9f4f3a3ec111fcf220724427f29b5157729a