Update for 0.2.0 release

This is the initial work to get ready for the Android Proximity Kit 0.2.0 release. It adds the ability to start and stop the Proximity Kit manager. This is demonstrated by providing a button in the UI for the end user to control.

This has been tested locally with a pre-release build.

**TODO:**

- [ ] When 0.2.0 is released replace the existing lib with it