Add neutron-lbaas-agent to exlude image for Ubuntu binary

UCA latest Newton release lack of neutron-lbaas-common package, disable
neutron-lbaas-agent for Ubuntu binary until they fix it.

TrivialFix

Change-Id: I2c02fc578cffe82918ae6affe6cf0e6095ae47e4
Signed-off-by: Jeffrey Zhang <zhang.lei.fly@gmail.com>