fix(secure-storage): add missing function

[danielsogl]

fix #1625

[ihadeed]

Could you please fix the lint issues

[danielsogl]

@ihadeed done!

[dexterouschen]

@danielsogl can you reopen this issue? the newest version of secure storage still haven't solve the inaccessibility of secureDevice(), sure you can access it on SecureStorageObject but this function only matters when the initialization fails, so the Promise rejection should at least include a object with secureDevice() on it. You can probably call it SecureStorageError, that way secureDevice() can be used in the same way as described in the plugin documentation:

https://github.com/Crypho/cordova-plugin-secure-storage#android

var ss;
var _init = function () {
    ss = new cordova.plugins.SecureStorage(
        function () {
            console.log('OK');
        },
        function () {
            navigator.notification.alert(
                'Please enable the screen lock on your device. This app cannot operate securely without it.',
                function () {
                    ss.secureDevice(
                        function () {
                            _init();
                        },
                        function () {
                            _init();
                        }
                    );
                },
                'Screen lock is disabled'
            );
        },
        'my_app');
};
_init();