Facebook SDK v4 LoginButton ignores XML customizations

I managed to get the desired result by following the following steps:

1. Opened the Facebook SDK 3.x LoginButton code and saw how the button was styled there:

   this.setBackgroundResource(R.drawable.com_facebook_button_blue);
   this.setCompoundDrawablesWithIntrinsicBounds(
                R.drawable.com_facebook_inverse_icon, 0, 0, 0);
   this.setCompoundDrawablePadding(getResources().getDimensionPixelSize(
                R.dimen.com_facebook_loginview_compound_drawable_padding));
   this.setPadding(getResources().getDimensionPixelSize(
                   R.dimen.com_facebook_loginview_padding_left),
               getResources().getDimensionPixelSize(
                   R.dimen.com_facebook_loginview_padding_top),
               getResources().getDimensionPixelSize(
                   R.dimen.com_facebook_loginview_padding_right),
               getResources().getDimensionPixelSize(
                   R.dimen.com_facebook_loginview_padding_bottom));
   

2. Based on the solution presented in this answer, I changed the button parameters during onPostCreate() as follows:

   float fbIconScale = 1.45F;
   Drawable drawable = hostActivity.getResources().getDrawable(
                                  com.facebook.R.drawable.com_facebook_button_icon);
   drawable.setBounds(0, 0, (int)(drawable.getIntrinsicWidth()*fbIconScale),
                            (int)(drawable.getIntrinsicHeight()*fbIconScale));
   authButton.setCompoundDrawables(drawable, null, null, null); 
   authButton.setCompoundDrawablePadding(hostActivity.getResources().
                     getDimensionPixelSize(R.dimen.fb_margin_override_textpadding));
   authButton.setPadding(
           hostActivity.getResources().getDimensionPixelSize(
                                                     R.dimen.fb_margin_override_lr),
           hostActivity.getResources().getDimensionPixelSize(
                                                    R.dimen.fb_margin_override_top),
           hostActivity.getResources().getDimensionPixelSize(
                                                     R.dimen.fb_margin_override_lr),
           hostActivity.getResources().getDimensionPixelSize(
                                                R.dimen.fb_margin_override_bottom));
   

   Where my custom dimensions are as follows:

   <dimen name="fb_margin_override_top">13dp</dimen>
   <dimen name="fb_margin_override_bottom">13dp</dimen>
   <!--The next value changes the margin between the FB icon and the left border:-->
   <dimen name="fb_margin_override_lr">10dp</dimen>
   <!--The next value changes the margin between the FB icon and the login text:-->
   <dimen name="fb_margin_override_textpadding">17dp</dimen>
   

This results in the desired layout: