In the previous code path, we will create an invisible anomaly preference and update it to visible if it contains any anomaly. However, when anomaly is dismissed we don't reset preference to invisible. So, this cl adds code to set it to invisible explicitly when anomaly list is empty. Bug: 64617126 Test: RunSettingsRoboTests Change-Id: Ie7a3498da91243f05f4c47fb1cc5f67b177d04b1