Native controls Android

# Feature Request

## Motivation Behind Feature
Implementing the native background controls function allows the user to stop the music even in the background (in my specific case a web radio)

## Feature Description
Simply native Android controls over Spotify-style background audio

The issue names no files, tests, or entry points. Start by inspecting the Android side of cordova-plugin-media and how background playback is handled; define the required Spotify-style controls and verify that stopping audio works while playback is in the background.

Written by the indexing model from the issue text.