Volume keys do not work with bt headset when during a call

[Evan Wang]

Arale, OTA4+ image #2, channel: ubuntu-touch/rc/meizu.en

Steps to reproduece:
1. Pair with a BT headset (BT headset type: EDIFIER W670BT)
2. Open dialer
3. Make a call
4. Increase/Decrease the volume by pressing the volume keys
5. Check the call volume from BT headset

Expected results:
The call volume from BT headset will change accordingly

Actual results:
The call volume from BT headset does not change

[Sebastien Bacher (seb128)]

the keys handling can't come from settings since that's not active all the time, likely for unity8 or indicator-sound

is the sound actually changing or are the keys not handled at all currently?

[Evan Wang (wsy324)]

The volume keys work fine with the BT headset with Music app, just could not change the sound from BT headset during a call.

[Sebastien Bacher (seb128)]

well, then it's a dialer-app issue maybe...