* Add check for `phone-context`.
Add a check to PhoneNumberUtil that the value of the `phone-context` parameter of the tel URI follows the correct syntax as defined in [RFC3966](https://www.rfc-editor.org/rfc/rfc3966#section-3).
* Add check for `phone-context`.
Add a check to PhoneNumberUtil that the value of the `phone-context` parameter of the tel URI follows the correct syntax as defined in [RFC3966](https://www.rfc-editor.org/rfc/rfc3966#section-3).
* Add check for `phone-context`.
Add a check to PhoneNumberUtil that the value of the `phone-context` parameter of the tel URI follows the correct syntax as defined in [RFC3966](https://www.rfc-editor.org/rfc/rfc3966#section-3).