shared: Split creation of mgmt_request into a separate function
shared: Split creation of mgmt_request into a separate function

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