Plugin does not use Android media volume

[spiffytech]

Expected Behaviour

Creating a WebRTC stream using the media stream plugin lets my app use Android's media volume

Actual Behaviour

App uses Android's telephone volume on some Android versions, ringer volume on others

Reproduce Scenario (including but not limited to)

Playing a WebRTC audio stream back out the phone's speakers

Steps to Reproduce

<audio autoplay></audio>
...
const stream = await navigator.mediaDevices.getUserMedia({audio: true, video: false})
myHtml5AudioElement.srcObject = stream;

Platform and Version (eg. Android 5.0 or iOS 9.2.1)

Android 7.1-8.1, at least

(Android) What device vendor (e.g. Samsung, HTC, Sony...)

Android emulator, OnePlus 5, Alcatel A574BL

Cordova CLI version and cordova platform version

$ phonegap cordova --version
8.0.0

$ phonegap cordova platform version android
Installed platforms:
  android 7.0.0
  browser 5.0.3
Available platforms:
  ios ~4.5.4
  osx ~4.0.1
  windows ~5.0.0
  www ^3.12.0

Plugin version

$ phonegap cordova plugin version | grep phonegap-plugin-media-stream
phonegap-plugin-media-stream 1.2.1 "MediaStream"