How to remove default layout's padding/margin

Question

I have the following layout files:

activity_main.xml

Answer 1

I know this is already answered question but, i just come across such an issue, the answer helped but not completely, as there was a right padding. I found out that, it is because of the padding set in the Theme i used. It might be helpful for those still see the padding. All you need to do is remove it.