Start foreground service from ConnectivityBackgroundTestActivity On TV, CtsVerifier is moved to background and gets frozen when the screen is off. This makes ConnectivityBackgroundTest fails since CtsVerifier can not continue connectivity test while it's frozen. This CL adds a foreground service and avoids CtsVerifier is being frozen. Test: CtsVerifier Bug: 284060686 Change-Id: If3c3edfd5f18bd8eb193676a0e009995b5e45ccd