android/AVDTP: Fix not removing start_timer source
android/AVDTP: Fix not removing start_timer source

It is possible that stream->start_timer can be set on stream_free which
should then should take care of remove it properly otherwise it can
trigger which would very likely cause a crash.

Thanks to Hannu Mallat <hannu.mallat@jolla.com> for reporting it.

silent-snowman/bluez,mapfau/bluez,ComputeCycles/bluez,ComputeCycles/bluez,silent-snowman/bluez,pstglia/external-bluetooth-bluez,ComputeCycles/bluez,pstglia/external-bluetooth-bluez,silent-snowman/bluez,mapfau/bluez,silent-snowman/bluez,pstglia/external-bluetooth-bluez,pkarasev3/bluez,mapfau/bluez,pkarasev3/bluez,pstglia/external-bluetooth-bluez,ComputeCycles/bluez,pkarasev3/bluez,pkarasev3/bluez,mapfau/bluez