Error: Invalid value, Input field allowing special characters

[juanfactor88]

Describe the bug
The international phone number input is allowing the user to enter special characters when using phone and number keyboard type. This not only doesn't look right visually but, sometimes leads to Invalid Value error when the user saves the value.

Package version
0.7.2

Flutter version
3.7.8

To Reproduce
Steps to reproduce the behavior:

use the example.
String initialCountry = 'US';
PhoneNumber number = PhoneNumber(isoCode: 'US');
keyboard type could be number or phone.
enter 4 numbers, then enter a special character (eg: . * , )
you'll get the invalid input error.

Expected behavior
You should only be able to enter numbers in the field because you're validating phone numbers.

Screenshots

** Targeted platforms (please complete the following information):**

• OS [e.g. Android, iOS, ...]
• Web [✔ or ❌]

Additional context
There should be a way to prevent the user to input anything other than numbers.