Make use of androids AudioManager (patch)

```
Nice to know that your working on this great program again!

I patched mindbell to use the AudioManager some time ago. So if you want, 
here’s the patch…
```

Original issue reported on code.google.com by `KMHans...@googlemail.com` on 3 Jun 2015 at 5:26

Attachments:
- [am.patch](https://storage.googleapis.com/google-code-attachments/mindbell/issue-43/comment-0/am.patch)
