stream-manager-dbus: Add new DBus methods to set preferred device

stream-manager-dbus: Add new DBus methods to set preferred device

  server          : org.pulseaudio.Server
  object path     : /org/pulseaudio/StreamManager
  interface       : org.pulseaudio.StreamManager

  method name     : SetStreamPreferredDevice
  method argument : unsigned int for stream index
                    unsidned int for device id
  return value    : string for return message
                    - success          : "STREAM_MANAGER_RETURN_OK"
                    - no match found   : "STREAM_MANAGER_RETURN_ERROR_DEVICE_NOT_FOUND"
                    - policy error     : "STREAM_MANAGER_RETURN_ERROR_POLICY"
                    - internal error   : "STREAM_MANAGER_RETURN_ERROR_INTERNAL"

[Version] 11.1.57
[Issue type] New feature

Change-Id: I2830efed90c7a76ca720766f1f01ab47db55ef03
Signed-off-by: Sangchul Lee <sc11.lee@samsung.com>