Voice Broadcast - Fix playback scrubbing not working if playback is stopped

[Florian14]

Type of change

• Feature
• Bugfix
• Technical
• Other :

Content

Fix voice broadcast listening not starting from the saved position.

Motivation and context

Fix #7961

Screenshots / GIFs

Tests

• Move the cursor of the seek bar of a voice broadcast
• Press the play button
• Then the playback should be started from the cursor position

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()

[ElementBot]

	Warnings
⚠️	Please add a reviewer to your PR.

Generated by 🚫 dangerJS against 960bb77

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

0.0% Coverage
0.0% Duplication

[bmarty]

LGTM!