Check UserAgent for "Android StockBrowser" without the Samsung Browser or Chrome Browser

isAndroidStockBrowser.js

function isAndroidStockBrowser() {
	var navU = navigator.userAgent;

	// Android Mobile
	var isAndroidMobile = navU.indexOf('Android') > -1 && navU.indexOf('Mozilla/5.0') > -1 && navU.indexOf('AppleWebKit') > -1;

	// Apple webkit
	var regExAppleWebKit = new RegExp(/AppleWebKit\/([\d.]+)/);
	var resultAppleWebKitRegEx = regExAppleWebKit.exec(navU);
	var appleWebKitVersion = (resultAppleWebKitRegEx === null ? null : parseFloat(regExAppleWebKit.exec(navU)[1]));

	// Chrome
	var regExChrome = new RegExp(/Chrome\/([\d.]+)/);
	var isChrome = regExChrome.exec(navU);

	// Native Android Browser
	var isAndroidBrowser = (isAndroidMobile && isChrome === null) && (appleWebKitVersion !== null && parseFloat(appleWebKitVersion) < parseFloat(537.36));
	return isAndroidBrowser;
}