Picker tray doesn't display picker *on first launch* on iOS 15 physical devices

[justintoth]

This is related to issue #258, which was concerning iOS 15 physical devices crashing due to the UIApplication.sharedApplication.keyWindow being null intermittently. Now that that is fixed, on first launch of the app when you tap on a dropdown it slides the tray up a little but with no picker in it.

However, if you either suspend and resume the app or force close it and reopen it, the tray renders correctly and you can see the picker:

Uninstalling the app and reinstalling it causes the issue to happen again. Updating the app also causes the issue to happen again. So basically, this is only an issue on first launch after a clean install or upgrade. Tested using the demo-ng project...