BLE Notifications - Update examples and libraries

The Cordova BLE plugin has been updated to automatically turn on/off the notification config descriptor when enabling/disabling notifications.

This means that code that turns on/off the config descriptor is no longer needed and should be removed from example apps and libraries.

Related repositories:

• https://github.com/evothings/evothings-libraries
• https://github.com/evothings/evothings-examples
• https://github.com/evothings/evothings-demos