fix(android): call WebView.stopLoading() from main thread

[garymathews]

• Allow Titanium.UI.WebView.stopLoading() to function when called from events

TEST CASE

const win = Ti.UI.createWindow();
const webView = Ti.UI.createWebView({ url: 'https://google.com/' });

webView.addEventListener('beforeload', e => {
    webView.stopLoading();
});

win.add(webView);
win.open();

JIRA Ticket

[build]

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Generated by 🚫 dangerJS against ce27c24

[ypbnv]

LGTM!

I did not see the discussion in the 8_1_X backport. Sorry!

[garymathews]

Closing, marked for 8_3_X