[TIMOB-20075] Android: Titanium.Network.addSystemCookie not adding cookie to webview

On SDK 5.0 Titanium.Network.addSystemCookie doesn't work as expected when trying to add cookies to a webview. In SDK 3.5 our code works fine. The use case is that a login is done in the main app and the session cookie returned needs to be used on our webviews. Here is the code that does that.

if (osname === 'android') {
    var sessionCookie = _.findWhere(
        Titanium.Network.getHTTPCookiesForDomain(
            Ti.App.Properties.getString('siteUrl').match(/^https?:\/\/(?:www\.)?([^\/^:]+)[:\/$]?/i)[1]
        ),
        {name: 'JSESSIONID'}
    );
    Titanium.Network.removeAllSystemCookies();
    Titanium.Network.addSystemCookie(sessionCookie);
}

I have confirmed that sessionCookie is correct and that it is not being used in the webview (using chrome inspect a simple ajax request doesn't send the cookie). This used to work fine on 3.5 (not sure about 4 though, we migrated 3.5 -> 5).