lib/Ext/device/contacts/Abstract.js
function(config) {
        config.callback.call(config.scope || this, config.label.toUpperCase(), config.label);
    }
function(config) {
        config.callback.call(config.scope || this, config.label.toUpperCase(), config.label);
    }
Returns localized, user readable label for a contact field (i.e. "Mobile", "Home")
**This method is for Sencha Native Packager only**

@return {String} user readable string