ios 13 beta 6 - inappbrowser is ignoring in-page dialogs

# Bug Report
- ios 13 beta 6
- "cordova-plugin-inappbrowser": "3.1.0"
- "@ionic-native/in-app-browser": "4.7.0"

issue: i try show popup confirm but inappbrowser is ignoring in-page dialogs, then result is always false.
example:
x = window.confirm("Confirm?");
x => alway return false

thanks.

No source file or test is named. Reproduce the issue with iOS 13 beta 6, cordova-plugin-inappbrowser 3.1.0, and @ionic-native/in-app-browser 4.7.0 using window.confirm("Confirm?"); inspect the iOS dialog handling, and consider the issue done when the returned value reflects the user's choice.

Written by the indexing model from the issue text.