[AC-1865] Android: Ti.App.addEventListener doesn't work inside a WebView under SDK 3.0

Under SDK 2.14, it was possible to trap App-level events inside a webview's javascript block by using Ti.App.addEventListener(). Under 3.0, this no longer seems to work. An easy workaround is to create a function inside the webview, then put the Ti.App.addEventListener code to the javascript module that hosts the webview. Then execute the function inside the webview using webview.evalJS('myfunction()');