bluetooth headphone is recognized as a keyboard

[Robin Heroldich]

I have a cheap Bluetooth Headphone, which worked in the past, but after BlueZ5 it doesn't work. My phone is recognized it as a keyboard. The sound is routed to it, but I can't use the volume buttons, which worked in the past.

Phone: Nexus 4 with rc-proped channel (BUT IT'S THE SAME WITH OTA-10 TOO)

current build number: 289
device name: mako
channel: ubuntu-touch/rc-proposed/bq-aquaris.en
last update: 2016-04-11 18:39:19
version version: 289
version ubuntu: 20160411
version device: 20160401.1
version custom: 20160330-9-vivid

BlueZ: Version: 5.37-0ubuntu5~overlay1

Headphone: SH-V447BL (Sport-s9)

phablet@ubuntu-phablet:~$ /usr/bin/bluez-list-devices
[NEW] Controller 30:30:30:31:30:33 Nexus 4 [default]
[NEW] Device 88:0F:10:88:E9:9A MI_SCALE
[NEW] Device 20:15:03:13:99:F1 SPORT-S9

[bluetooth]# devices
Device 88:0F:10:88:E9:9A MI_SCALE
Device 20:15:03:13:99:F1 SPORT-S9

[bluetooth]# info 20:15:03:13:99:F1
Device 20:15:03:13:99:F1
        Name: SPORT-S9
        Alias: SPORT-S9
        Class: 0x002540
        Icon: input-keyboard
        Paired: yes
        Trusted: yes
        Blocked: no
        Connected: yes
        LegacyPairing: no
        UUID: Headset (00001108-0000-1000-8000-00805f9b34fb)
        UUID: Audio Sink (0000110b-0000-1000-8000-00805f9b34fb)
        UUID: A/V Remote Control Target (0000110c-0000-1000-8000-00805f9b34fb)
        UUID: Advanced Audio Distribu.. (0000110d-0000-1000-8000-00805f9b34fb)
        UUID: A/V Remote Control (0000110e-0000-1000-8000-00805f9b34fb)
        UUID: Handsfree (0000111e-0000-1000-8000-00805f9b34fb)
        UUID: Human Interface Device... (00001124-0000-1000-8000-00805f9b34fb)