Hi Serkan,
I have exactly the same issue Agentry 7.x for Android - Complex table search column width, I'm not sure if create an incident in SAP since for me it seems a bug that you can't control that, but as you can see I found some kind of work around that requires the user to know that he can do that.
Copy&Paste from my own thread:
I discovered that if user double taps to the column header, the width will be adjusted to the longest text displayed. Maybe it will be enough for my case, but I think developers should have a way to control that... it is not too obvious for users that they can do that.