The onFocusChildPositioned API introduced in aosp/1965665 currently ONLY works when the focused child is in the same composable, and does not work if the focused child is an AndroidView or inside an AndroidView, even if it's another composition inside the AndroidView.

This is because this API was required to fix an issue in the foundation module, and because it's new and still @Experimental needed to live in the foundation module. The AndroidView wiring is all done in the ui module however, and we don't allow cross-module experimental dependencies, so the android wiring couldn't happen yet.

Design doc