Elastic Rtc Recorder Endpoint Ios Playback Problem

[Lethea]

Hi I use elasticrtc for kurento auto scale instance group.
Now we try to record video + audio.
It records perfect but
while trying to play in ios
it can not be played because of the Audio codec MPEG Audio Layer ½
I found a solution

GstCaps *ac = gst_caps_from_string ("audio/mpeg,mpegversion=1,layer=3");
in kurento github list.

However I want to ask that
if I change this on the instance
the new instance that elasticrtc create will not include right ?

So can you fix the problem on base image ?
Then I'll create new service on it ?