A full bleed button that is always visible through the scroll or a button at the bottom of the screen

I am making an Android app. This is how the screen goes. The screen has is scrollable and at the bottom there is a button Submit. Now there are two ways of showing this button.

1) Have it placed outside the ScrollView. In which case the button is always visible.

2) Have it inside the ScrollView. In this case the the user has to scroll down to the bottom to access the button.

What should my decisions be based on for choosing one of the above methods? Or What are the pros and cons of each method?