refactor(cdk/overlay): re-add internal workaround (angular#32395)

Re-adds a workaround for an internal bug.

(cherry picked from commit 21cc21e)

Author: crisbeto

src/cdk/overlay/overlay.ts

@@ -89,14 +89,15 @@ export function createOverlayRef(injector: Injector, config?: OverlayConfig): Ov
     ? overlayConfig.positionStrategy?.getPopoverInsertionPoint?.()
     : null;
 
+  // Note: this is redundant since the host will be moved into its final location immediately
+  // after. We're keeping it as a temporary workaround, because an internal team depends on
+  // this behavior. We can roll this back after January 5th 2026.
+  overlayContainer.getContainerElement().appendChild(host);
+
   if (isElement(customInsertionPoint)) {
     customInsertionPoint.after(host);
   } else if (customInsertionPoint?.type === 'parent') {
     customInsertionPoint.element.appendChild(host);
-  } else {
-    // Note: leave the container for last so that we fall
-    // back to it for unsupported/newly-added values.
-    overlayContainer.getContainerElement().appendChild(host);
   }
 
   return new OverlayRef(