Voice Broadcast - Rework internal media players coordination

[Florian14]

Type of change

• Feature
• Bugfix
• Technical
• Other :

Content

• Rework internal media player coordination:
  Fix multiple media player created in the same time
  Properly cancel and release media player in preparation if needed
• Remove some legacy code related to the live listening (we don't need to check anymore the playback position)
• Fix playback restart handling

Motivation and context

Prevent potential media player leaked and improve voice broadcast playback

Screenshots / GIFs

Tests

• Play voice broadcasts (live & ended)
• Change the current voice broadcast in the fly, play with the buttons

Tested devices

• Physical
• Emulator
• OS version(s):

Checklist

• Changes has been tested on an Android device or Android emulator with API 21
• UI change has been tested on both light and dark themes
• Accessibility has been taken into account. See https://github.com/vector-im/element-android/blob/develop/CONTRIBUTING.md#accessibility
• Pull request is based on the develop branch
• Pull request includes a new file under ./changelog.d. See https://github.com/vector-im/element-android/blob/develop/CONTRIBUTING.md#changelog
• Pull request includes screenshots or videos if containing UI changes
• Pull request includes a sign off
• You've made a self review of your PR
• If you have modified the screen flow, or added new screens to the application, you have updated the test UiAllScreensSanityTest.allScreensTest()

[sonarcloud]

SonarCloud Quality Gate failed.   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

0.0% Coverage
0.0% Duplication

[bmarty]

Thanks, LGTM (not tested)!