android - Action Bar icon size

Question

According to Action Bar Icons action bar icon for the mdpi screen should be 24 x 24 px but the icons in Action Bar Icon Pack for mdpi are 32 x 32 px. The sizes do not match for other screen sizes neither. So which one is correct and what dimensions should the action bar icon have?

Answer 1

-------update 2015.10.17--------

The new google design gideline says:"System icons are displayed at 24dp","Icon content is limited to the 20 x 20dp live area, with 4px of trim around the perimeter".Like:

------old-------

Full asset, 32x32 dp; Optical square, 24x24 dp