VoIP: Setting audio output to speakers is reverted to phone at each connection loss

**Describe the bug**
During a 1-on-1 call, whenever Element loses the connection and reconnects, the audio output device is reset to default (phone instead of speakers in my case).

**To Reproduce**
Steps to reproduce the behavior:
1. Do a 1-on-1 phone call.
2. Set audio output to speakers
3. Wait for a connection loss
4. Audio output will be reset to the default (phone)

**Expected behavior**
Audio output should stay set on the deviced last selected by user during the phone call (speakers in my case).

**Smartphone (please complete the following information):**
- Device: Huawei P10
- OS: Android 9

**Additional context**
- App version and store: 1.0.17 [40100172] (G-b1275) - Google Play Store
- Homeserver: matrix.org