redirect file:///android_asset/www call to http(s)://localhost

[nirinasp]

As assets are served from https://localhost for Android (cordova-android v10.x.x), directly calling file:///android_asset/www + / + filename generates cors issue when other assets are loaded after the webview rendered the main page (index.html). These are little modifications on the SalesforceDroidGapActivity.java file which mainly redirect all url load from file:///android_asset/www to http(s)/localhost

[salesforce-cla[bot]]

Thanks for the contribution! Before we can merge this, we need @nirinasc to sign the Salesforce.com Contributor License Agreement.