MaterialTextField + Choices input type crashes when running in iPhone device

## 🐛 Bug Report

App crashes when page is loaded with the following xaml directly on iPhone.

Output from debugger:
019-02-15 14:55:22.781 SystemCoreTests[31549:16758495] error: * Assertion at ../../../../../mono/mini/interp/interp.c:1965, condition `is_ok (error)' not met, function:do_jit_call, Attempting to JIT compile method '(wrapper unknown) object:gsharedvt_out_sig (intptr,int&,intptr)' while running in aot-only mode. See https://docs.microsoft.com/xamarin/ios/internals/limitations for more information.
assembly: type: member:(null)

### Expected behavior
Work as it does in the simulator
### Reproduction steps

use the following xaml with a view model that has a List and bind to it.

### Configuration
XF 4.7 latest
iPhone SE running 13.5

Works on all simulators running 13.5

**Version:** 1.x

**Platform:**
- [ X ] :iphone: iOS
- [ ] :robot: Android
- [ ] :checkered_flag: WPF
- [ ] :earth_americas: UWP
- [ ] :apple: MacOS
- [ ] :tv: tvOS
- [ ] :monkey: Xamarin.Forms