Unable to access shared localStorage when a local page is loaded (iOS 13.6.0 and 4.0.0)

# Bug Report

## Problem
Using cordova-plugin-inappbrowser@4.0.0 localStorage values are unaccessible.
In @3.2.0 this works fine.

How to reproduce:

Allow with your index.html create another html file such as test.html.
at index.html you must set a localStorage value.
In test.html you must attempt to read that value.

Expected: Value is defined
Current: Value is undefined

iOS Version: 13.6.0
Plugin Version: 4.0.0

Reproduce the issue using index.html and test.html on iOS 13.6 with plugin versions 3.2.0 and 4.0.0, confirming whether the localStorage value is shared between the pages. Then inspect the plugin's iOS implementation for the version change affecting local page storage. Done means the value set in index.html is readable from test.html on version 4.0.0.

Written by the indexing model from the issue text.