docs: Fixed code snippet in notify-user/navigation.html

notifyIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK |

        Intent.FLAG_ACTIVITY_CLEAR_TASK);

// Creates the PendingIntent

PendingIntent notifyIntent =

PendingIntent pendingIntent =

        PendingIntent.getActivity(

        this,

        0,

);

// Puts the PendingIntent into the notification builder

builder.setContentIntent(notifyIntent);

builder.setContentIntent(pendingIntent);

// Notifications are issued by sending them to the

// NotificationManager system service.

NotificationManager mNotificationManager =