IsTextAllCaps and IsAutoCapitalizationEnabled no longer working

## 🔙 Regression

Text is lower case by default and cannot be auto capitalized.

### Old (and correct) behaviour
Using IsTextAllCaps resulted in all text in MaterialTextField being capitalized. Using IsAutoCapitalizationEnabled resulted in the first letter of the string in a MaterialTextField being capitalized .

### Current behaviour
All text is lowercase by default. This issue appeared in version 1.6.1

### Reproduction steps
1. Update to XF-Material-Library version 1.6.1
2. Apply either IsTextAllCaps or IsAutoCapitalizationEnabled to a MaterialTextField.
3. Compare with the behaviour expected in XF-Material-Library version 1.6.0

### Configuration

**Version:** 1.6.1 (and still an issue in 1.6.4)

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