Cupertino dialog horizontal divider is not showing correctly in dark mode #158522
Description
Regression introduced by #150410
The horizontal divider that separates the body of the Cupertino dialog from the actions is not correctly picking up the right color in dark mode, so it appears darker than it should. The dividers between different actions are showing up correctly.
As shown here:
The left image is a native dialog, the right is a CupertinoAlertDialog on master.
More details here.