How do I remove radius corners programmatically?

I want to programmatically remove the radius of a corner. I do not know how to do that.

I am creating a ProgressBarCompat to change the color of the progress bar with colorAccent, but I have no idea how to remove the corner radius in progressBarDrawable in android api below 11.

Drawable link: https://android.googlesource.com/platform/frameworks/base/+/master/core/res/res/drawable/progress_horizontal.xml

Can I do it?

I use this to make progress available:

LayerDrawable drawable = (LayerDrawable) getProgressDrawable();
Drawable progressDrawable = drawable.findDrawableByLayerId(android.R.id.progress);
// and now i detect sdk version and call method to remove corners on this drawable (progressDrawable).