Eleven: request record audio permission for visualizer

Visualizer needs audio recording permission.

* set visualizer to disabled by default
* ask for audio recording permission when visualizer is enabled
* fix a case where visualizer visibility would be set multiple times in a row
* if visualizer is enabled but audio recording permission is not granted
  ask for it when the audio player fragment gets focus

Change-Id: I2c175915cc686ce37e6e94d113e767a75ef68492