Fix Task Launcher sink test on CF tile environment

[ilayaperumalg]

Currently, the dataflowTaskLauncherSink test goes by the default http://dataflow-server:9393 as the dataflow client server URI on the CF tile environment as the task launcher sink test isn't configured to use in CF tile environment as the necessary dataflow client authentication properties aren't set correctly when using the CF tile environment as the underlying test infrastructure.