bug(ios): not all keyboards are visible on sys-keyboard picker until tap and scroll

**Describe the bug**

When are there more than four keyboards installed on the FV for iOS on iPad, the keyboard menu doesn't show all keyboards. One might wonder where the rest of the keyboards go after being installed.

**To Reproduce**

1. On FV/Keyman app, install at least 6 keyboards
2. Enable FV/Keyman app as a system keyboard
3. go to Safari and switch to FV/Keyman and longpress on the globe key
4. See error

**Expected behavior**

The scrollbar is a helpful indicator that there are more keyboards installed, but it isn't always shown. It might be helpful to show the keyboard being selected instead of the default presentation of the keyboard menu, i.e. instead of taking the selected keyboard to the top of the list, just automatically make it visible with the tick.

**Screenshots**

FV:
Skicinuwatuwewakon keyboard was selected, but it's not visible until tap and scroll to the bottom of the keyboard menu.

Keyman for iOS:
Myanmar keyboard is selected, but not shown right away until tap and scroll.

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**Keyman for iPad:**
- Device: iPad mini 6
- OS: iOS 15.4.1
- Keyman version. 16.0.5-alpha
- Target application: FV/Keyman app