Skip startVisibilityMonitoring test on portrait screen devices.

Due to an RRO issue on user bulid, ClusterHomeService is not disabled,
thus explicitly skip the test for now until the RRO issue is resolved.

Bug: 333488161

Test: android.car.cluster.cts.ClusterHomeManagerTest

Change-Id: Iaae5709981f5c2f4519d20f521605c6b75c8af08